fix(JitsiConference) make sure leave always resolves

modules/xmpp/ChatRoom.js

@@ -1867,6 +1867,7 @@ export default class ChatRoom extends Listenable {
                 // let's just clean
                 this.connection.emuc.doLeave(this.roomjid);
                 this.clean();
+                resolve();
             }
         }));