### Environment

* Dubbo version: dubbo-registry-nacos 2.7.6
* Operating System version: Win10
* Java version: JAVA 8

### Steps to reproduce this issue
1 springboot  yml配置如下： 
registry:
     address: nacos://127.0.0.1:8848
     simplified: true
     group: dubbo-local
  metadata-report:
            address: nacos://127.0.0.1:8848
            group: dubbo-local

2 登陆nacos 1.2.1 控制台发现元数据 group配置生效，但是服务管理下的group依旧是DEFAULT_GROUP。

3 跟了下dubbo-registry-nacos 2.7.6的代码 发现在调用NamingService中 没有传入配置的group参数，使用的默认组参数 
 public void doRegister(URL url) {
        String serviceName = this.getServiceName(url);
        Instance instance = this.createInstance(url);
        this.execute((namingService) -> {
            namingService.registerInstance(serviceName, instance);
        });
    }

Pls. provide [GitHub address] to reproduce this issue.

### Expected Result

What do you expected from the above steps？

### Actual Result

What actually happens?

If there is an exception, please attach the exception trace:

```
Just put your stack trace here!
```

serviceNames.addAll(firstPageData);
            
            int count = listView.getCount();
            
            int pageNumbers = count / PAGINATION_SIZE;
            int remainder = count % PAGINATION_SIZE;
            
            if (remainder > 0) {
                pageNumbers += 1;
            }
            
            while (pageIndex < pageNumbers) {
                listView = namingService.getServicesOfServer(++pageIndex, PAGINATION_SIZE);
                serviceNames.addAll(listView.getData());
            }
        });
        return serviceNames;
    }
    private void filterServiceNames(Set<String> serviceNames, URL url) {
        final List<String> categories = getCategories(url);
        final String targetServiceInterface = url.getServiceInterface();
        final String targetVersion = url.getParameter(VERSION_KEY, "");
        final String targetGroup = url.getParameter(GROUP_KEY, "");
        filterData(serviceNames, serviceName -> {
            
            
            
            
            
            String[] segments = serviceName.split(SERVICE_NAME_SEPARATOR, -1);