Use `id` instead of `updated_at` for more consistent behavior

modules/backend/models/ImportModel.php

@@ -195,7 +195,7 @@ abstract class ImportModel extends Model
         $file = $this
             ->import_file()
             ->withDeferred($sessionKey)
-            ->orderBy('updated_at', 'desc')
+            ->orderBy('id', 'desc')
             ->first()
         ;