CBQE-0 :: Fix vbucket dist failure when hard failover is used

Change-Id: Ic805e2ba068a61cceed4c6e8995eba4ff2c2ac91
Reviewed-on: http://review.couchbase.org/39690
Reviewed-by: Thuan Nguyen <soccon@gmail.com>
Reviewed-by: Parag Agarwal <agarwal.parag@gmail.com>
Tested-by: Parag Agarwal <agarwal.parag@gmail.com>