Remove special case that logs alerts and credentials differently.

Because sanitize handles this for us.

Change-Id: I9763a13b13392aaf99299cbcc10855caff4bfd0f
Reviewed-on: http://review.couchbase.org/37132
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Reviewed-by: Artem Stemkovski <artem@couchbase.com>