#PR:4109 Reference create proxy faild and retry create may lead to OOM

[vio-lin]

• I have searched the issues of this repository and believe that this is not a duplicate.
• I have checked the FAQ of this repository and believe that this is not a duplicate.

Environment

• Dubbo version: 2.7.0
• Operating System version: Windows7
• Java version: jdk8

Steps to reproduce this issue

1. stop dubbo service
2. dubbo client set checked = true. do get cudbbo client for times.
3. the size of list field [urls] in ReferenceConfig wil increase

Pls. provide [GitHub address] to reproduce this issue.
(project)[https://github.com/vio-lin/incubator-dubbo/tree/error-situation]
run java file
incubator-dubbo\dubbo-demo\dubbo-demo-xml\dubbo-demo-xml-consumer\src\main\java\org\apache\dubbo\demo\consumer\Application.java

Expected Result

the [urls] in ReferenceConfig will be updated.

Actual Result

the avalidable registery urls be add to [urls] in ReferenceConfig