QmlDesigner: Update AnchorIndicatorGraphicsItem after updating anchorlines

Change-Id: Ibdde4d8a32abac8bc7b1572507c7a8094d28f604
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>

src/plugins/qmldesigner/components/formeditor/anchorindicatorgraphicsitem.cpp

@@ -228,6 +228,7 @@ void AnchorIndicatorGraphicsItem::updateAnchorIndicator(const AnchorLine &source
     updateAnchorLinePoints(&m_targetAnchorLineFirstPoint, &m_targetAnchorLineSecondPoint, targetAnchorLine);
 
     updateBoundingRect();
+    update();
 }
 
 void AnchorIndicatorGraphicsItem::updateBoundingRect()