redis pubsub: cannot close publisher

[Li Ma]

Traceback (most recent call last):
  File "dragonflow/tests/fullstack/test_pub_sub.py", line 311, in test_pub_sub_register_addr
    self.stop_publisher(publisher)
  File "dragonflow/tests/fullstack/test_pub_sub.py", line 60, in stop_publisher
    publisher.close()
  File "dragonflow/db/pubsub_drivers/redis_db_pubsub_driver.py", line 62, in close
    self.client.client_kill(self.remote)
  File "/opt/stack/new/dragonflow/.tox/fullstack/local/lib/python2.7/site-packages/redis/client.py", line 604, in client_kill
    return self.execute_command('CLIENT KILL', address)
  File "/opt/stack/new/dragonflow/.tox/fullstack/local/lib/python2.7/site-packages/redis/client.py", line 573, in execute_command
    return self.parse_response(connection, command_name, **options)
  File "/opt/stack/new/dragonflow/.tox/fullstack/local/lib/python2.7/site-packages/redis/client.py", line 585, in parse_response
    response = connection.read_response()
  File "/opt/stack/new/dragonflow/.tox/fullstack/local/lib/python2.7/site-packages/redis/connection.py", line 582, in read_response
    raise response
redis.exceptions.ResponseError: No such client

In Redis PUB/SUB driver, the publisher cannot be closed. This happens in this commit:
https://review.openstack.org/#/c/452614/

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/453042

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/453042
Committed: https://git.openstack.org/cgit/openstack/dragonflow/commit/?id=d3f55e81b0752a56d05b408cae2dd096d0ee8f5a
Submitter: Jenkins
Branch: master

commit d3f55e81b0752a56d05b408cae2dd096d0ee8f5a
Author: Hong Hui Xiao <email address hidden>
Date: Tue Apr 4 15:20:20 2017 +0800

    Disconnect connection to close a redis publisher

    redis.client_kill is to kill a client, while self.remote
    is a ip:port of redis server.

    Just disconnect all the connection of publisher's redis
    client for closing redis publisher.

    The corresponding is at https://review.openstack.org/#/c/452614/

    Change-Id: If4080c613ab5ebe34dd5e461f8045f1b4c6f1c48
    Closes-Bug: #1678926