MB-100: log more push_keys-replicated keys

Change-Id: I936501dddc2b0be59d2a6a8273176c069e7e292c
Reviewed-on: http://review.couchbase.org/30116
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Artem Stemkovski <artem@couchbase.com>