MB-24217 remove duplicate roles before assigning roles to user
MB-24217 remove duplicate roles before assigning roles to user

Change-Id: I43ef8091f57cd69e3e8e98908f1577fa589dec57
Reviewed-on: http://review.couchbase.org/77734
Tested-by: Artem Stemkovski <15a0730a27c69f62ab86f2b6c639fca202166c02@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