- [x] I have searched the [issues](https://github.com/apache/dubbo/issues) of this repository and believe that this is not a duplicate.
- [x] 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: 2.7.1
* Operating System version: windows10
* Java version: java8

### Steps to reproduce this issue

I run the [code](https://github.com/dubbo-x/example/tree/master/java-dubbo-consul2) by follow steps:

- docker run -p 8400:8400 -p 8500:8500 -p 8600:8600 -d consul
- run provider
- run consumer

### Actual Result

- provider runs ok
- consumer fail with `no provider available`

So I trace the register and subscribe process:

- provider register result show below

![register](https://user-images.githubusercontent.com/16648345/59485088-f48b5c80-8ea6-11e9-9be1-63a02472150d.png)

and we can see it use `url.getServiceInterface()` as service name (this example is `dubbo.DubboService`)

https://github.com/apache/dubbo/blob/6f3a05ca820dc6e3dab127cd9a5daa375709347a/dubbo-registry/dubbo-registry-consul/src/main/java/org/apache/dubbo/registry/consul/ConsulRegistry.java#L255-L265

- however if we add group and version info, consumer will use `url.getServiceKey()` to find service (this example is `dubbo-x/dubbo.DubboService:0.0.1`), which doesn't equal the service name

https://github.com/apache/dubbo/blob/6f3a05ca820dc6e3dab127cd9a5daa375709347a/dubbo-registry/dubbo-registry-consul/src/main/java/org/apache/dubbo/registry/consul/ConsulRegistry.java#L141-L144

So consumer will not find the service if we add group and version info. Is my configuration wrong?

URL empty = URLBuilder.from(consumerURL)
                .setProtocol(EMPTY_PROTOCOL)
                .removeParameter(CATEGORY_KEY)
                .build();
        List<URL> result = new ArrayList<URL>();
        result.add(empty);
        return result;
    }
    private NewService buildService(URL url) {
        NewService service = new NewService();
        service.setAddress(url.getHost());
        service.setPort(url.getPort());
        service.setId(buildId(url));
        service.setName(url.getServiceInterface());
        service.setCheck(buildCheck(url));
        service.setTags(buildTags(url));
        service.setMeta(Collections.singletonMap(URL_META_KEY, url.toFullString()));
        return service;
    }
    private List<String> buildTags(URL url) {
        Map<String, String> params = url.getParameters();
        List<String> tags = params.keySet().stream()
                .map(k -> k + "=" + params.get(k))
                .collect(Collectors.toList());
        tags.add(SERVICE_TAG);
        return tags;
    }
    private String buildId(URL url) {
        
        return Integer.toHexString(url.hashCode());