Qt: Only dynamically reset video scale if a game is running

CHANGES

@@ -1,3 +1,7 @@
+0.9.0: (Future)
+Other fixes:
+ - Qt: Only dynamically reset video scale if a game is running
+
 0.8.0: (2020-01-21)
 Features:
  - Improved logging configuration

src/platform/qt/DisplayGL.cpp

@@ -356,8 +356,10 @@ void PainterGL::resizeContext() {
 		return;
 	}
 
+	if (m_started) {
 		mCore* core = m_context->thread()->core;
 		core->reloadConfigOption(core, "videoScale", NULL);
+	}
 
 	QSize size = m_context->screenDimensions();
 	m_backend->setDimensions(m_backend, size.width(), size.height());