MB-5904 remove passwords from ns_config log traces

Change-Id: Iec21b815018e2321d469dd2062b32ec459260009
Reviewed-on: http://review.couchbase.org/28091
Tested-by: Artem Stemkovski <artem@couchbase.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>