Merge pull request celery#1793 from dhackner/master

'Reject' semipredicate example corrections

Author: ask

docs/userguide/tasks.rst

@@ -955,13 +955,12 @@ Example requeuing the message:
 
 .. code-block:: python
 
-    import errno
     from celery.exceptions import Reject
 
     @app.task(bind=True, acks_late=True)
     def requeues(self):
         if not self.request.delivery_info['redelivered']:
-            raise Requeue('no reason', requeue=True)
+            raise Reject('no reason', requeue=True)
         print('received two times')
 
 Consult your broker documentation for more details about the ``basic_reject``