我们使用方法分组来用dubbo，每个分组有自己权限，但是dubbo:registry标签 username & password 不生效，
让我不得不使用
```
    <dubbo:registry
            address="zookeeper://username:pwd@ip:port"
            group="xxx"/>
```
这种写法失效
```
    <dubbo:registry
            address="zookeeper://ip:port"
            username="username"
            password="pwd"/>
```

import static org.apache.dubbo.rpc.cluster.Constants.REFER_KEY;
import static org.apache.dubbo.rpc.cluster.Constants.TAG_KEY;
/**
 * AbstractDefaultConfig
 *
 * @export
 */
public abstract class AbstractInterfaceConfig extends AbstractMethodConfig {
    private static final long serialVersionUID = -1559314110797223229L;
    /**
     * Local impl class name for the service interface
     */
    protected String local;
    /**
     * Local stub class name for the service interface
     */
    protected String stub;
    /**
     * Service monitor
     */
    protected MonitorConfig monitor;
    /**
     * Strategies for generating dynamic agents，there are two strategies can be choosed: jdk and javassist
     */
    protected String proxy;
    /**
     * Cluster type
     */
    protected String cluster;
    /**