chord_unlock now uses default_retry_delay

celery/app/builtins.py

@@ -315,7 +315,7 @@ def add_chord_task(app):
         accept_magic_kwargs = False
         ignore_result = False
 
-        def run(self, header, body, partial_args=(), interval=1, countdown=1,
+        def run(self, header, body, partial_args=(), interval=None, countdown=1,
                 max_retries=None, propagate=None, eager=False, **kwargs):
             propagate = default_propagate if propagate is None else propagate
             group_id = uuid()