MB-100 Don't log vclock twice when conflict happens.

It's part of the raw value. So it was logged twice introducing certain
confusion.

Change-Id: I071c238c39d4e994c0740bac15df51f8e6663b51
Reviewed-on: http://review.couchbase.org/30072
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Reviewed-by: Artem Stemkovski <artem@couchbase.com>