Ticket #4426: code clean up before 4.8.30 release.

(erase_dir_after_copy): don't call g_queue_is_empty() if erase_list is NULL.
erase_list is NULL in case of move an empty directory across filesystems.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>

src/filemanager/file.c

@@ -1574,7 +1574,7 @@ static void
 erase_dir_after_copy (file_op_total_context_t * tctx, file_op_context_t * ctx,
                       const vfs_path_t * vpath, FileProgressStatus * status)
 {
-    if (ctx->erase_at_end)
+    if (ctx->erase_at_end && erase_list != NULL)
     {
         /* Reset progress count before delete to avoid counting files twice */
         tctx->progress_count = tctx->prev_progress_count;