Task.retry now forwards message headers. Closes #3017

celery/app/task.py

@@ -580,6 +580,7 @@ class Task(object):
             'soft_time_limit': limit_soft,
             'time_limit': limit_hard,
             'reply_to': request.reply_to,
+            'headers': request.headers,
         }
         options.update(
             {'queue': queue} if queue else (request.delivery_info or {})