http:// prefix for api.config.servers.websocket.clientUrl

My app and api are hosted on different ports. I tried to edit the default setting 'window.location.origin' to something like '127.0.0.1:8080' wich Primus doesn't seem to like (It tried to connect to 'ws://primus/?....'). Adding the http:// prefix to the url caused Uglify to throw during server boot. This PR should fix this.