MDL-30391 Backup: Exception in restore should be thrown as it is to b…

…e handled by calling function

backup/restore.php

@@ -46,7 +46,7 @@
             $restore->execute();
         } catch(Exception $e) {
             $restore->cleanup();
-            throw new moodle_exception((string)$e);
+            throw $e;
         }
     } else {
         $restore->save_controller();