Don't convert the opaque to host order when decoding upr responses

Change-Id: I14aedb0de89f62a949260a3a5d3b692c5622152c
Reviewed-on: http://review.couchbase.org/31032
Reviewed-by: Artem Stemkovski <artem@couchbase.com>
Tested-by: Artem Stemkovski <artem@couchbase.com>