syncX() doesn't do anything anymore. Remove it.

Change-Id: Id15af428e1d04606564bad093847b3dc5a731e85
Reviewed-by: Dmytro Poplavskiy <dmytro.poplavskiy@nokia.com>

src/gsttools/qgstreamervideowidget.cpp

@@ -159,9 +159,6 @@ bool QGstreamerVideoWidgetControl::eventFilter(QObject *object, QEvent *e)
             WId newWId = m_widget->winId();
             if (newWId != m_windowId) {
                 m_windowId = newWId;
-                // Even if we have created a winId at this point, other X applications
-                // need to be aware of it.
-                QApplication::syncX();
                 setOverlay();
             }
         }