NCBC-638: If Server is null when sending an operation then retry operation

Change-Id: Idfee0ab2852c51cb9c7de1912374d64ee1633be7
Reviewed-on: http://review.couchbase.org/41374
Tested-by: Jeffry Morris <jeffrymorris@gmail.com>
Reviewed-by: Brett Lawson <brett19@gmail.com>