Make sure UPR connection is unique by the name.

Fix the logic regarding naming UPR connection and checking for
the correct name for exsiting one before it's created.

Change-Id: I4a5c68872e20ac7b62e091f3e21734b75eab3bde
Reviewed-on: http://review.couchbase.org/31737
Tested-by: David Liao <david.liao@couchbase.com>
Reviewed-by: Chiyoung Seo <chiyoung@couchbase.com>