Fix notifier task not queued if failed

cynomys/tasks.py

@@ -92,7 +92,7 @@ def notify_email(delta_id, attempts):
     # Email was not sent, retry
     logger.error("failed to send email to {}, attempts left: {}".format(receivers, attempts))
     if attempts > 0:
-        notify_email(receivers, delta_id, attempts)
+        notify_email.delay(receivers, delta_id, attempts)
 
 
 def check_delta(responsebool, return_value, parent_task):