configcenter bug for zookeeper

[cifaz]

Environment

• Dubbo version: 2.7.2
• Operating System version: window10 1903
• Java version: jdk1.8

Steps to reproduce this issue

1. create app router in dubbo admin
2. request my url
3. no response the app router

Pls. provide [GitHub address] to reproduce this issue.

Expected Result

No response or listner for the app condition router

Actual Result

We add the app condition router, it should be invoke in routerChain.route, The reason is ZookeeperDynamicConfiguration

rootPath = "/" + url.getParameter(CONFIG_NAMESPACE_KEY, DEFAULT_GROUP) + "/config";

Tips: 
CONFIG_NAMESPACE_KEY = org.apache.dubbo.configcenter.Constants.CONFIG_NAMESPACE_KEY = config.namespace (dubbo-configcenter-api)

But the zookeeper config is dubbo.config-center.namespace = dubbo, If I change to my own config, em, dubbo.config-center.namespace = dev, It cannot work

[iwhalecloud-platform]

2.7.3已修复

[chickenlj]

Fxied in 2.7.3, and will be released in few days.