Pass proxied engine's handle instead of our own for unknown_command
Pass proxied engine's handle instead of our own for unknown_command

Change-Id: I74d30c08b20345d673d6f05f05cd63d7ed259bf9
Reviewed-on: http://review.northscale.com:8080/369
Reviewed-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>
Tested-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>

membase/bucket_engine,membase/bucket_engine,membase/bucket_engine,membase/bucket_engine,couchbase/bucket_engine,couchbase/bucket_engine,couchbase/bucket_engine,couchbase/bucket_engine