CCBC-414: Assign cccp cookie when sending over server struct

We never assigned to cccp->cmdcookie

Change-Id: Ibfaaf2f6c590d1af684c83d29bc461122ffe741d
Reviewed-on: http://review.couchbase.org/37321
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Brett Lawson <brett19@gmail.com>