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"/>
```

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package org.apache.dubbo.config;
import org.apache.dubbo.common.URL;
import org.apache.dubbo.common.URLBuilder;
import org.apache.dubbo.common.Version;
import org.apache.dubbo.common.config.Environment;
import org.apache.dubbo.common.extension.ExtensionLoader;
import org.apache.dubbo.common.utils.Assert;
import org.apache.dubbo.common.utils.CollectionUtils;
import org.apache.dubbo.common.utils.ConfigUtils;