ClientThread类62行bug

[LeiRui]

		if (config.DB_SWITCH.equals("IoTDB") && !config.USE_PREPARE_STATEMENT
				&& config.USE_SESSION) {
			session = new Session(config.host, config.port, Constants.USER, Constants.PASSWD);
		}
		try {
			session.open();
		} catch (IoTDBSessionException e) {
			e.printStackTrace();
		}

当config中USE_SESSION是false的时候，这里会报错

[liuruiyiyang]

Fixed