Fix freezing the UE editor when quitting game mode after capturing.

The FEvent was triggered on Stop but directly reset into the waiting
state afterwards.
Removing resetting correctly terminates the thread.

Source/Plugins/NVSceneCapturer/Source/NVSceneCapturer/Private/NVImageExporter.cpp

@@ -424,7 +424,6 @@ void FNVImageExporter_Thread::Stop()
     {
         // Trigger the event so the thread doesn't wait anymore
         HavePendingImageEvent->Trigger();
-        HavePendingImageEvent->Reset();
     }
 }