Add the proper number of arguments to upr stream log message

Change-Id: I761e49f11cde1b40eb6d76f93f20bdb970c4a85c
Reviewed-on: http://review.couchbase.org/32753
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>