QWidgetWindow: handle ShortcutOverride events

ShortcutOverride events sent to the QWindow should be handled by the
QWidget.

Change-Id: Icec504db1066871b02dec639e4c1c624b0afeaa8
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>
Reviewed-by: Morten Johan Sørvig <morten.sorvig@nokia.com>

src/widgets/kernel/qwidgetwindow_qpa.cpp

@@ -124,6 +124,7 @@ bool QWidgetWindow::event(QEvent *event)
 
     case QEvent::KeyPress:
     case QEvent::KeyRelease:
+    case QEvent::ShortcutOverride:
         handleKeyEvent(static_cast<QKeyEvent *>(event));
         return true;