Bug 1565: Leaving a folder with a large amount of files takes long

https://winscp.net/tracker/1565

Source commit: 80d88ddca3d0f7a942dbcc662df8f28acb56514d

source/packages/my/NortonLikeListView.pas

@@ -217,7 +217,7 @@ procedure TCustomNortonLikeListView.Delete(Item: TListItem);
 var
   Index: Integer;
 begin
-  if FLastDeletedItem <> Item then
+  if (FLastDeletedItem <> Item) and (not FClearingItems) then
   begin
     Index := Item.Index;