fixed subsriber url setting

git-svn-id: https://svn.apache.org/repos/asf/incubator/streams/trunk@1442113 13f79535-47bb-0310-9956-ffa450edef68
adding configuration of subscribers to be json object

git-svn-id: https://svn.apache.org/repos/asf/incubator/streams/trunk@1442114 13f79535-47bb-0310-9956-ffa450edef68