### 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

@Override
    @Parameter(key = EXPORTER_LISTENER_KEY, append = true)
    public String getListener() {
        return listener;
    }
    @Override
    public void setListener(String listener) {
        checkMultiExtension(ExporterListener.class, "listener", listener);
        this.listener = listener;
    }
    public Boolean isRegister() {
        return register;
    }
    public void setRegister(Boolean register) {
        this.register = register;
    }
    public Integer getWarmup() {
        return warmup;
    }
    public void setWarmup(Integer warmup) {
        this.warmup = warmup;
    }
    public String getSerialization() {
        return serialization;
    }
    public void setSerialization(String serialization) {
        this.serialization = serialization;
    }
}