Edited Issue: Designer: Assert thrown when tests launch the model wizard [1456]

I am seeing this assert when the tests launch the model wizard. This is new, I haven't seen this before.


```
---------------------------
Assertion Failed: Abort=Quit, Retry=Debug, Ignore=Continue
---------------------------
unexpected Guid.Empty value for data source guid



at Microsoft.Data.Entity.Design.VisualStudio.ModelWizard.Engine.DataConnectionUtils.GetConnectionProperties(IVsDataProviderManager dataProviderManager, IVsDataConnection dataConnection)

at Microsoft.Data.Entity.Design.VisualStudio.ModelWizard.Engine.DataConnectionUtils.GetInitialCatalog(IVsDataProviderManager dataProviderManager, IVsDataConnection dataConnection)

at Microsoft.Data.Entity.Design.VisualStudio.ModelWizard.Gui.WizardPageDbConfig.GetDefaultAppConfigEntryName(IVsDataConnection dataConnection)

at Microsoft.Data.Entity.Design.VisualStudio.ModelWizard.Gui.WizardPageDbConfig.SetDataConnection(IVsDataConnection dataConnection)

at Microsoft.Data.Entity.Design.VisualStudio.ModelWizard.Gui.WizardPageDbConfig.NewDataSourceSelected()

at Microsoft.Data.Entity.Design.VisualStudio.ModelWizard.Gui.WizardPageDbConfig.dataSourceComboBox_SelectedIndexChanged(Object sender, EventArgs e)

at System.Windows.Forms.ComboBox.OnSelectedIndexC......

<truncated>
---------------------------
Abort Retry Ignore
---------------------------

```

Full stack trace

```
> EFDesigner.QA.APITest.EscherDSL.dll!Microsoft.DP.Tools.Common.APITest.EscherDSL.RemotableWrappers.Wizards.ModelBuilderWizardFormTestObject.Next.AnonymousMethod__0() Line 77 + 0x16 bytes C#
[Native to Managed Transition]
mscorlib.dll!System.Delegate.DynamicInvokeImpl(object[] args) + 0x76 bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbackDo(System.Windows.Forms.Control.ThreadMethodEntry tme) + 0xaf bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(object obj) + 0x63 bytes
mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) + 0xa7 bytes
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) + 0x16 bytes
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0x41 bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallback(System.Windows.Forms.Control.ThreadMethodEntry tme) + 0x95 bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbacks() + 0x120 bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.WndProc(ref System.Windows.Forms.Message m) + 0x11d bytes
System.Windows.Forms.dll!System.Windows.Forms.ScrollableControl.WndProc(ref System.Windows.Forms.Message m) + 0x2a bytes
System.Windows.Forms.dll!System.Windows.Forms.ContainerControl.WndProc(ref System.Windows.Forms.Message m) + 0x10 bytes
System.Windows.Forms.dll!System.Windows.Forms.Form.WndProc(ref System.Windows.Forms.Message m) + 0x40 bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.OnMessage(ref System.Windows.Forms.Message m) + 0x11 bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.WndProc(ref System.Windows.Forms.Message m) + 0x39 bytes
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DebuggableCallback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) + 0x5e bytes
[Native to Managed Transition]
[Managed to Native Transition]
System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.LocalModalMessageLoop(System.Windows.Forms.Form form) + 0xf2 bytes
System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(int reason, System.Windows.Forms.ApplicationContext context) + 0x1c6 bytes
System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoop(int reason, System.Windows.Forms.ApplicationContext context) + 0x4a bytes
System.Windows.Forms.dll!System.Windows.Forms.Application.RunDialog(System.Windows.Forms.Form form) + 0x33 bytes
System.Windows.Forms.dll!System.Windows.Forms.Form.ShowDialog(System.Windows.Forms.IWin32Window owner) + 0x32c bytes
Microsoft.WizardFramework.dll!Microsoft.WizardFramework.WizardForm.Start(System.Windows.Forms.IWin32Window parent) + 0xe7 bytes
Microsoft.WizardFramework.dll!Microsoft.WizardFramework.WizardForm.Start() + 0x7 bytes
Microsoft.Data.Entity.Design.dll!Microsoft.Data.Entity.Design.VisualStudio.ModelWizard.ModelObjectItemWizard.RunStarted(object automationObject, System.Collections.Generic.Dictionary<string,string> replacementsDictionary, Microsoft.VisualStudio.TemplateWizard.WizardRunKind runKind, object[] customParams) + 0x762 bytes
Microsoft.VisualStudio.TemplateWizard.dll!Microsoft.VisualStudio.TemplateWizard.Wizard.Execute(object application, int hwndOwner, ref object[] ContextParams, ref object[] CustomParams, ref EnvDTE.wizardResult retval) + 0x1738 bytes
[Native to Managed Transition]
[Managed to Native Transition]
EFDesigner.QA.APITest.VS.dll!Microsoft.DP.Tools.Common.APITest.VS.ToolWindows.SolutionExplorer.ProjectTestObject.AddNewItemToProjectViaTemplate(string itemTemplateFullPath, string fileFullName, Microsoft.DP.Tools.Common.APITest.VS.ToolWindows.SolutionExplorer.ProjectItemTestObject parent) Line 305 + 0xf bytes C#
EFDesigner.QA.APITest.VS.dll!Microsoft.DP.Tools.Common.APITest.VS.ToolWindows.SolutionExplorer.ProjectTestObject.AddNewItemToProjectViaTemplate(string itemTemplateFullPath, string fileFullName) Line 319 + 0x11 bytes C#
EFDesigner.QA.APITest.VS.dll!Microsoft.DP.Tools.Common.APITest.VS.RemotableWrappers.DTEProject.AddProjectItemFromTemplate(string name, string itemTemplateitemName) Line 251 + 0x1a bytes C#
[Native to Managed Transition]
EFDesigner.QA.APITest.VS.dll!Microsoft.DP.Tools.Common.APITest.VS.RemotableWrappers.Driver.RemoteObjectManager.ExecuteFunctionCall.AnonymousMethod__9(object[] targetArgs) Line 176 + 0x36 bytes C#
[Native to Managed Transition]
mscorlib.dll!System.Delegate.DynamicInvokeImpl(object[] args) + 0x76 bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbackDo(System.Windows.Forms.Control.ThreadMethodEntry tme) + 0xaf bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(object obj) + 0x63 bytes
mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) + 0xa7 bytes
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) + 0x16 bytes
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0x41 bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallback(System.Windows.Forms.Control.ThreadMethodEntry tme) + 0x95 bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbacks() + 0x120 bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.WndProc(ref System.Windows.Forms.Message m) + 0x11d bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.OnMessage(ref System.Windows.Forms.Message m) + 0x11 bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.WndProc(ref System.Windows.Forms.Message m) + 0x39 bytes
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DebuggableCallback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) + 0x5e bytes

```