change admin_user is so it doesn't conflict with regular users
change admin_user is so it doesn't conflict with regular users

Change-Id: Iccd6962c253e39dc7abd59aeacbd5e2510f2f8a0
Reviewed-on: http://review.couchbase.org/75117
Tested-by: Artem Stemkovski <15a0730a27c69f62ab86f2b6c639fca202166c02@couchbase.com>
Reviewed-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>

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