tdf#115998 base: crash on delete relationship

Change-Id: Ida8cc9ef0b812254990ac808f78ae183ae28a1c0
Reviewed-on: https://gerrit.libreoffice.org/50633Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

dbaccess/source/ui/querydesign/TableWindow.cxx

@@ -490,6 +490,7 @@ void OTableWindow::Remove()
 {
     // Delete the window
     OJoinTableView* pTabWinCont = getTableView();
+    VclPtr<OTableWindow> aHoldSelf(this); // keep ourselves alive during the RemoveTabWin process
     pTabWinCont->RemoveTabWin( this );
     pTabWinCont->Invalidate();
 }