MB-11459: Add debug logging for high seqno incorrectly set

Change-Id: I44e80cf415f8b7c4bba70a9b684301534e026c03
Reviewed-on: http://review.couchbase.org/38606
Reviewed-by: abhinav dangeti <abhinav@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>