dubbo2.6.12版本下,注册的url上表示dubbo版本号的参数dubbo用了默认值2.0.2,而没有用Version.getVersion()获取真正的版本

- [ ] I have searched the [issues](https://github.com/apache/dubbo/issues) of this repository and believe that this is not a duplicate.

### Environment

* Dubbo version: 2.6.12
* Operating System version: xxx
* Java version: 1.8

### Steps to reproduce this issue
在2.6.2中 url上版本号参数设置为:map.put("dubbo", Version.getVersion());
在2.6.12中,变成了map.put("dubbo", Version.getProtocolVersion());