MB-22973 better error message for malformed roles
MB-22973 better error message for malformed roles

Change-Id: I2b0dc5019a2a2ccee0ae4dd70552110c04df51ec
Reviewed-on: http://review.couchbase.org/77733
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