QLabel already does that for QPixmap, so just do the same for
QMovie's current pixmap.
Task-number: QTBUG-48157
Change-Id: I7b26460f778e56ff017a5efd433f8929f30e4b41
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>