- [ ] I have searched the [issues](https://github.com/apache/dubbo/issues) of this repository and believe that this is not a duplicate.
- [ ] I have checked the [FAQ](https://github.com/apache/dubbo/blob/master/FAQ.md) of this repository and believe that this is not a duplicate.

### Environment

* Dubbo version: 2.7.x
* Operating System version: Mac OS
* Java version: N/A

### Steps to reproduce this issue

Run dubbo-demo project

1. Use consul as registry center
2. Start provider
3. Start consumer

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

### Expected Result

The consumer can exit as usual

### Actual Result

The consumer cannot exit.

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

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

private URL url;
        private long consulIndex;
        private boolean running;
        ConsulNotifier(URL url, long consulIndex) {
            this.url = url;
            this.consulIndex = consulIndex;
            this.running = true;
        }
        @Override
        public void run() {
            while (this.running) {
                if (ANY_VALUE.equals(url.getServiceInterface())) {
                    processServices();
                } else {
                    processService();
                }
            }
        }
        private void processService() {