### 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!
```

final Instance instance = createInstance(url);
        execute(namingService -> namingService.registerInstance(serviceName, instance));
    }
    @Override
    public void doUnregister(final URL url) {
        execute(namingService -> {
            String serviceName = getServiceName(url);
            Instance instance = createInstance(url);
            namingService.deregisterInstance(serviceName, instance.getIp(), instance.getPort());
        });
    }
    @Override
    public void doSubscribe(final URL url, final NotifyListener listener) {
        Set<String> serviceNames = getServiceNames(url, listener);
        
        if(isServiceNamesWithCompatibleMode(url)){
            for(String serviceName:serviceNames){
                NacosInstanceManageUtil.setCorrespondingServiceNames(serviceName, serviceNames);
            }
        }
        doSubscribe(url, listener, serviceNames);
    }
    private void doSubscribe(final URL url, final NotifyListener listener, final Set<String> serviceNames) {
        execute(namingService -> {
            if (isServiceNamesWithCompatibleMode(url)) {
                List<Instance> allCorrespondingInstanceList = Lists.newArrayList();
                /**
                 * Get all instances with serviceNames to avoid instance overwrite and but with empty instance mentioned
                 * in https://github.com/apache/dubbo/issues/5885 and https://github.com/apache/dubbo/issues/5899
                 */