fix(JitsiConference): skip participant kicked event for kicker

With the introduction of lobby the ChatRoom KICKED event is now also emitted for
ourselves (the kicker) so we want to avoid emitting an event where `undefined`
kicked someone.

JitsiConference.js

  * this is the id of the participant which was kicked.
  */
 JitsiConference.prototype.onMemberKicked = function(isSelfPresence, actorId, kickedParticipantId) {
+    // This check which be true when we kick someone else. With the introduction of lobby
+    // the ChatRoom KICKED event is now also emitted for ourselves (the kicker) so we want to
+    // avoid emitting an event where `undefined` kicked someone.
+    if (actorId === this.myUserId()) {
+        return;
+    }
+
     const actorParticipant = this.participants[actorId];
 
     if (isSelfPresence) {