Strope 加入 MUC

connection.muc.join("abc@conference.sand.chinacloudapp.cn",
    "15002",
    room_message,
    on_presence,
    on_roster, "000000");

connection.muc.join("abc@conference.sand.chinacloudapp.cn", "15002", room_message, on_presence, on_roster, "000000");