#4312 Move handleMdiWindowClosed call from widget destructors to MdiSubWindow closeEvent

* This way the mdi window still exists at the time of removal and we can handle the removal orderly

ApplicationCode/UserInterface/RiuWellLogPlot.cpp

@@ -85,7 +85,6 @@ RiuWellLogPlot::~RiuWellLogPlot()
     if (m_plotDefinition)
     {
         m_plotDefinition->detachAllCurves();
-        m_plotDefinition->handleMdiWindowClosed();
     }
 }