Gameplay Tag Query - Assert when changing root expression while tag picker is open

Changing a gameplay tag query's root expression in a make query node will assert if the tag editor widget is open. 

• Create a Make Gameplay tag query node
• Set the RootExpression to All Tags Match (doesn't matter exactly)
• Open up the Edit button to set a Tag
• While that Tag picker is open, change the RootExpression

> [Inline Frame] UE4Editor-Slate.dll!TArray<void ,TSizedDefaultAllocator<32>>::RangeCheck(int Index) Line 674 C+> [Inline Frame] UE4Editor-Slate.dll!TArray<void *,TSizedDefaultAllocator<32>>::RangeCheck(int Index) Line 674 C  [Inline Frame] UE4Editor-Slate.dll!TArray<void *,TSizedDefaultAllocator<32>>::operator[](int) Line 718 C  [Inline Frame] UE4Editor-Slate.dll!TIndirectArray<FSimpleSlot,TSizedDefaultAllocator<32>>::operator[](int) Line 125 C  [Inline Frame] UE4Editor-Slate.dll!TPanelChildren<FSimpleSlot>::operator[](int) Line 472 C  UE4Editor-Slate.dll!SMenuAnchor::ResetPopupMenuContent() Line 604 C  UE4Editor-Slate.dll!SMenuAnchor::SetIsOpen(bool InIsOpen, const bool bFocusMenu, const int FocusUserIndex) Line 576 C  UE4Editor-PropertyEditor.dll!SPropertyEditorEditInline::OnClassPicked(UClass * InClass) Line 268 C  [Inline Frame] UE4Editor-PropertyEditor.dll!Invoke(void(SPropertyEditorEditInline::)(UClass )) Line 65 C  [Inline Frame] UE4Editor-PropertyEditor.dll!UE4Tuple_Private::TTupleBase<TIntegerSequence<unsigned int>>::ApplyAfter(void(SPropertyEditorEditInline::)(UClass ) &) Line 299 C  UE4Editor-PropertyEditor.dll!TBaseRawMethodDelegateInstance<0,SPropertyEditorEditInline,void _cdecl(UClass *),FDefaultDelegateUserPolicy>::ExecuteIfSafe(UClass * <Params_0>) Line 469 C  [Inline Frame] UE4Editor-ClassViewer.dll!TDelegate<void __cdecl(UClass *),FDefaultDelegateUserPolicy>::ExecuteIfBound(UClass * <Params_0>) Line 599 C  UE4Editor-ClassViewer.dll!SClassViewer::OnClassViewerSelectionChanged(TSharedPtr<FClassViewerNode,0> Item, ESelectInfo::Type SelectInfo) Line 1828 C  [Inline Frame] UE4Editor-ClassViewer.dll!Invoke(void(SClassViewer::)(TSharedPtr<FClassViewerNode,0>, ESelectInfo::Type)) Line 65 C  [Inline Frame] UE4Editor-ClassViewer.dll!UE4Tuple_Private::TTupleBase<TIntegerSequence<unsigned int>>::ApplyAfter(void(SClassViewer::*)(TSharedPtr<FClassViewerNode,0>, ESelectInfo::Type) &) Line 299 C  UE4Editor-ClassViewer.dll!TBaseSPMethodDelegateInstance<0,SClassViewer,0,void __cdecl(TSharedPtr<FClassViewerNode,0>,enum ESelectInfo::Type),FDefaultDelegateUserPolicy>::ExecuteIfSafe(TSharedPtr<FClassViewerNode,0> <Params_0>, ESelectInfo::Type <Params_1>) Line 307 C  [Inline Frame] UE4Editor-ClassViewer.dll!TDelegate<void __cdecl(TSharedPtr<FClassViewerNode,0>,enum ESelectInfo::Type),FDefaultDelegateUserPolicy>::ExecuteIfBound(TSharedPtr<FClassViewerNode,0>) Line 599 C  UE4Editor-ClassViewer.dll!SListView<TSharedPtr<FClassViewerNode,0>>::Private_SignalSelectionChanged(ESelectInfo::Type SelectInfo) Line 947 C  UE4Editor-ClassViewer.dll!STableRow<TSharedPtr<FString,0>>::OnMouseButtonUp(const FGeometry & MyGeometry, const FPointerEvent & MouseEvent) Line 617 C  [Inline Frame] UE4Editor-Slate.dll!FSlateApplication::RoutePointerUpEvent::l8::<lambda_cc5aea9e7377b04ce85c30c65ec3889b>::operator()(const FArrangedWidget &) Line 4829 C  UE4Editor-Slate.dll!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_cc5aea9e7377b04ce85c30c65ec3889b>>(FSlateApplication * ThisApplication, FEventRouter::FToLeafmostPolicy RoutingPolicy, FPointerEvent EventCopy, const FSlateApplication::RoutePointerUpEvent::l8::<lambda_cc5aea9e7377b04ce85c30c65ec3889b> & Lambda, ESlateDebuggingInputEvent DebuggingInputEvent) Line 378 C  UE4Editor-Slate.dll!FSlateApplication::RoutePointerUpEvent(const FWidgetPath & WidgetsUnderPointer, const FPointerEvent & PointerEvent) Line 4815 C  UE4Editor-Slate.dll!FSlateApplication::ProcessMouseButtonUpEvent(const FPointerEvent & MouseEvent) Line 5356 C  UE4Editor-Slate.dll!FSlateApplication::OnMouseUp(const EMouseButtons::Type Button, const FVector2D CursorPos) Line 5321 C  UE4Editor-ApplicationCore.dll!FWindowsApplication::ProcessDeferredMessage(const FDeferredWindowsMessage & DeferredMessage) Line 2178 C  UE4Editor-ApplicationCore.dll!FWindowsApplication::DeferMessage(TSharedPtr<FWindowsWindow,0> & NativeWindow, HWND_ * InHWnd, unsigned int InMessage, unsigned _int64 InWParam, __int64 InLParam, int MouseX, int MouseY, unsigned int RawInputFlags) Line 2642 C  UE4Editor-ApplicationCore.dll!FWindowsApplication::ProcessMessage(HWND_ * hwnd, unsigned int msg, unsigned _int64 wParam, __int64 lParam) Line 1046 C  UE4Editor-ApplicationCore.dll!FWindowsApplication::AppWndProc(HWND_ * hwnd, unsigned int msg, unsigned __int64 wParam, __int64 lParam) Line 878 C+