fdo#86708 paint after Undo of Sort

Regression of 10fc1383 that exchanged
the PostPaint with SetDirty, but the paint is also needed.

Change-Id: Ic3e81fa106f405568effaed71ab33b575b4c5c5c

sc/source/ui/undo/undosort.cxx

@@ -49,6 +49,9 @@ void UndoSort::Execute( bool bUndo )
     rDoc.SetDirty(maParam.maSortRange);
     if (!aParam.mbUpdateRefs)
         rDoc.BroadcastCells(aParam.maSortRange, SC_HINT_DATACHANGED);
+
+    pDocShell->PostPaint(maParam.maSortRange, PAINT_GRID);
+    pDocShell->PostDataChanged();
 }
 
 }