MB-10415 use memcached password for cbcollect_info

Change-Id: I50486bde1176125f5eff8bdfeaafe9f0e0e217fc
Reviewed-on: http://review.couchbase.org/35571
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Artem Stemkovski <artem@couchbase.com>