Review incubator-shenyu-client-golang #15 pr

[Lisandro]

Dear community:

 The  incubator-shenyu-client-golang has new  pr,please review the code.Here is 
this pr main function:1. Adjust Example code
2.Refactor nacos client judgement logic
Here is link   
https://github.com/apache/incubator-shenyu-client-golang/pull/15/files