We print the following messages even if there is no stream_session with
that peer. It is a bit confusing.
INFO 2016-09-23 08:26:37,254 [shard 0] stream_session - stream_manager:
Close all stream_session with peer = 127.0.0.1 in on_restart
INFO 2016-09-23 08:26:37,287 [shard 0] stream_session - stream_manager:
Close all stream_session with peer = 127.0.0.3 in on_remove
Print only when the streaming session with the peer exists.