MB-11168: do not allow incoming replications of node key deletes

We do that only for _this_ node's keys and that's due to assumption
that node key deletions are part of ejecting node from cluster.

In this case accepting those deletions might break this node's ability
to leave cluster.

Change-Id: I8ce1dca18e6fcd1280a1bc9e21ca03bd7de3ecaa
Reviewed-on: http://review.couchbase.org/37417
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>