MB-26117: Move the following information from ns_server debug log to info log.
MB-26117: Move the following information from ns_server debug log to info log.

1. Rebalance Id
2. Nodes affected by rebalance

Change-Id: I613ca6da9d4691d171713177a108fd6efb052a61
Reviewed-on: http://review.couchbase.org/86726
Tested-by: Abhijeeth Nuthan <c984f83ff185d65ff5101a0e4554989c5828e94c@couchbase.com>
Reviewed-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>

membase/ns_server,membase/ns_server,membase/ns_server,membase/ns_server,membase/ns_server,membase/ns_server