### Environment

* Dubbo version: 2.7.3
* Operating System version: CentOS7
* Java version: 1.8

### Steps to reproduce this issue

1. Set two protocal, with different "register" attribute

```xml
<dubbo:protocol name="dubbo" port="8751" register="true"  />
<dubbo:protocol name="hessian" port="8752" register="false" />
```

2. use the zookeeper registry center

```xml
<dubbo:registry address="..." file="./.dubbo_cache" />
```

3. start the server and view the provider in zkCli


### Expected Result
only the dubbo is registed

### Actual Result
the dubbo and hession protocol are registed

}
        List<ProviderConfig> providers = new ArrayList<ProviderConfig>(protocols.size());
        for (ProtocolConfig provider : protocols) {
            providers.add(convertProtocolToProvider(provider));
        }
        return providers;
    }
    @Deprecated
    private static ProtocolConfig convertProviderToProtocol(ProviderConfig provider) {
        ProtocolConfig protocol = new ProtocolConfig();
        protocol.setName(provider.getProtocol().getName());
        protocol.setServer(provider.getServer());
        protocol.setClient(provider.getClient());
        protocol.setCodec(provider.getCodec());
        protocol.setHost(provider.getHost());
        protocol.setPort(provider.getPort());
        protocol.setPath(provider.getPath());
        protocol.setPayload(provider.getPayload());
        protocol.setThreads(provider.getThreads());
        protocol.setParameters(provider.getParameters());
        return protocol;
    }
    @Deprecated
    private static ProviderConfig convertProtocolToProvider(ProtocolConfig protocol) {
        ProviderConfig provider = new ProviderConfig();
        provider.setProtocol(protocol);
        provider.setServer(protocol.getServer());
        provider.setClient(protocol.getClient());
        provider.setCodec(protocol.getCodec());
        provider.setHost(protocol.getHost());