CBQE-1127 check bucket type before insert key using mc_bin_client

Change-Id: I167b6ec887498953956eda8ca57c6a065254b96b
Reviewed-on: http://review.couchbase.org/27324
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Tommie McAfee <tommie@couchbase.com>