service添加空构造函数

@bean
public DingdingService dingdingService() {
DingdingService dingdingService = new DingdingService();
// 设置全局的手机号或者token，可选
// dingdingService.setPhone("13121939122");
// dingdingService.setToken("dingdingtokne");
return dingdingService;
}