register add depEnv to metadata

[jarily]

我们线上ecs和k8s目前网络不通

所以我们有一个中心Prometheus，ecs和k8s上面各部署一个Prometheus把数据push到中心Prometheus

但是呢，我们的etcd又是通的，即注册到了同一个etcd里面

所以两个环境的confd处理监控数据的时候，无法区分哪个是ecs哪个是k8s，都能拉到同一份数据

要区分的话，首先肯定是注册前缀可以区分

但是有一个问题，未来网络扁平化落地后网络互通实现后，在服务从ecs切到k8s时，

由于注册键不一样，业务方也要跟着改配置

[codecov]

Codecov Report

Merging #346 (f8319cf) into master (c942559) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #346      +/-   ##
==========================================
+ Coverage   57.88%   57.90%   +0.01%     
==========================================
  Files          81       81              
  Lines        3087     3088       +1     
==========================================
+ Hits         1787     1788       +1     
  Misses       1134     1134              
  Partials      166      166              

Flag	Coverage Δ
unittests	57.90% <100.00%> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
server/server.go	100.00% <100.00%> (ø)