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"/>
```

* The {@link Filter} when the provider side exposed a service or the customer side references a remote service used,
     * if there are more than one, you can use commas to separate them
     */
    protected String filter;
    /**
     * The Listener when the provider side exposes a service or the customer side references a remote service used
     * if there are more than one, you can use commas to separate them
     */
    protected String listener;
    /**
     * The owner of the service providers
     */
    protected String owner;
    /**
     * Connection limits, 0 means shared connection, otherwise it defines the connections delegated to the current service
     */
    protected Integer connections;
    /**
     * The layer of service providers
     */
    protected String layer;
    /**
     * The application info
     */
    protected ApplicationConfig application;
    /**
     * The module info
     */
    protected ModuleConfig module;
    /**