CppTools: Do not access kits in non-UI thread

Amends 9c3420120e.

Change-Id: Iba8b1069bf4468119c7f518c562e4229141ac66b
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/cpptools/cppmodelmanager.h

@@ -282,6 +282,7 @@ private:
     void onSourceFilesRefreshed() const;
     void onCurrentEditorChanged(Core::IEditor *editor);
     void onCoreAboutToClose();
+    void setupFallbackProjectPart();
 
     void initializeBuiltinModelManagerSupport();
     void delayedGC();