fix(load-test): Uses websocket if available and adds room param to the connection url.

resources/load-test/load-test-participant.js

  * That function is called when connection is established successfully
  */
 function onConnectionSuccess() {
-    room = connection.initJitsiConference(roomName, config);
+    room = connection.initJitsiConference(roomName.toLowerCase(), config);
     room.on(JitsiMeetJS.events.conference.TRACK_ADDED, onRemoteTrack);
     room.on(JitsiMeetJS.events.conference.CONFERENCE_JOINED, onConferenceJoined);
     room.on(JitsiMeetJS.events.conference.USER_JOINED, id => {
 
 JitsiMeetJS.init(config);
 
+config.serviceUrl = config.bosh = `${config.websocket || config.bosh}?room=${roomName.toLowerCase()}`;
+
 connection = new JitsiMeetJS.JitsiConnection(null, null, config);
 connection.addEventListener(JitsiMeetJS.events.connection.CONNECTION_ESTABLISHED, onConnectionSuccess);
 connection.addEventListener(JitsiMeetJS.events.connection.CONNECTION_FAILED, onConnectionFailed);