### 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

// 
        String hostToRegistry = getValueFromConfig(protocolConfig, DUBBO_IP_TO_REGISTRY);
        if (hostToRegistry != null && hostToRegistry.length() > 0 && isInvalidLocalHost(hostToRegistry)) {
            throw new IllegalArgumentException("Specified invalid registry ip from property:" + DUBBO_IP_TO_REGISTRY + ", value:" + hostToRegistry);
        } else if (StringUtils.isEmpty(hostToRegistry)) {
            // 
            hostToRegistry = hostToBind;
        }
        map.put(ANYHOST_KEY, String.valueOf(anyhost));
        return hostToRegistry;
    }
    /**
     * Register port and bind port for the provider, can be configured separately
     * Configuration priority: environment variable -> java system properties -> port property in protocol config file
     * -> protocol default port
     *
     * @param protocolConfig
     * @param name
     * @return
     */
    private Integer findConfigedPorts(ProtocolConfig protocolConfig, String name, Map<String, String> map) {
        Integer portToBind = null;
        // 
        String port = getValueFromConfig(protocolConfig, DUBBO_PORT_TO_BIND);
        portToBind = parsePort(port);
        // 
        if (portToBind == null) {
            portToBind = protocolConfig.getPort();
            if (provider != null && (portToBind == null || portToBind == 0)) {
                portToBind = provider.getPort();