log upr stream_request command

Change-Id: I75c6aaac9eacb88058f7027eaf416317dc0e2474
Reviewed-on: http://review.couchbase.org/37762
Reviewed-by: Artem Stemkovski <artem@couchbase.com>
Tested-by: Artem Stemkovski <artem@couchbase.com>