vrplayer: some minor fixes

vrplayer/main.cpp

@@ -4,9 +4,9 @@
 
 int main(int argc, char *argv[])
 {
+    QApplication::setGraphicsSystem(QLatin1String("native"));
     QApplication a(argc, argv);
     MainWindow w;
     w.show();
-    
     return a.exec();
 }