[BUG] <DiscoveryUpstreamDataRefresh cacheConfigData方法GROUP_CACHE.get(ConfigGroupEnum.PROXY_SELECTOR) >

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

every 5 second interval, console print log:

o.a.s.s.data.http.HttpSyncDataService : Group config changed: [DISCOVER_UPSTREAM]

### Expected Behavior

@Override
public ConfigData cacheConfigData() {
return GROUP_CACHE.get(ConfigGroupEnum.DISCOVER_UPSTREAM);
}

### Steps To Reproduce

start Admin, start Bootstrap

### Environment

```markdown
ShenYu version(s): v2.6.1, master
```

### Debug logs

_No response_

### Anything else?

_No response_

Start at DiscoveryUpstreamDataRefresh.cacheConfigData() and inspect the GROUP_CACHE lookup for ConfigGroupEnum.PROXY_SELECTOR versus ConfigGroupEnum.DISCOVER_UPSTREAM. Reproduce by starting Admin and Bootstrap, then verify that the DISCOVER_UPSTREAM group is not logged as changed every five seconds.

Written by the indexing model from the issue text.