Use 12000 as UPR port

For development Couchbase is normally started via ./cluster_run.
There the UPR port 12000. Hence change to this port for now.

Change-Id: If6abe5678cb03fead2d922846bebd4b0bce50335
Reviewed-on: http://review.couchbase.org/32323
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Filipe David Borba Manana <fdmanana@gmail.com>