成员变化的时候时间更新为空问题处理

src/server/endpoints/v2/session.endpoint.js

@@ -200,7 +200,7 @@ router.put(APIv2.Sessions.Participant, function (req, res) {
 */
router.post(APIv2.Sessions.ParticipantUpdate, function (req, res) {
    let payload = req.body;
    let testing = ObjectUtil.fieldsCheck(payload, 'user_id', 'old_user_id', 'session_id');
    let testing = ObjectUtil.fieldsCheck(payload, 'user_id', 'session_id');
    if (!testing.pass) {
        throw testing.message;
    }