Move to single buffered rendering

Change-Id: I48d7688a3024c73e1de0fbefa15e3792d1444955

main.cpp

@@ -27,6 +27,7 @@ int main(int argc, char *argv[])
     format.setRedBufferSize(8);
     format.setGreenBufferSize(8);
     format.setBlueBufferSize(8);
+    format.setSwapBehavior(QSurfaceFormat::SingleBuffer);
     QSurfaceFormat::setDefaultFormat(format);
 
     QGuiApplication app(argc, argv);