bugfix: address list change events leak

[BeiKeJieDeLiuLangMao]

Ⅰ. Describe what this PR did

Fix etcd registry service's server address list change events leak.

Ⅱ. Does this pull request fix one issue?

#1623

Ⅲ. Why don't you add test cases (unit test/integration test)?

No new api.

Ⅳ. Describe how to verify it

1. get newest server address list then start debug break point
2. change server address list
3. cancel break point, then add change listener
4. receive change event，refresh address list

Ⅴ. Special notes for reviews

[codecov-io]

Codecov Report

Merging #1629 into develop will decrease coverage by 0.05%.
The diff coverage is 0%.

@@              Coverage Diff              @@
##             develop    #1629      +/-   ##
=============================================
- Coverage      47.19%   47.14%   -0.06%     
  Complexity      1778     1778              
=============================================
  Files            362      362              
  Lines          13227    13237      +10     
  Branches        1640     1641       +1     
=============================================
- Hits            6243     6240       -3     
- Misses          6307     6319      +12     
- Partials         677      678       +1

Impacted Files	Coverage Δ	Complexity Δ
...covery/registry/etcd3/EtcdRegistryServiceImpl.java	11.36% <0%> (-0.94%)	3 <0> (ø)
...server/store/file/FileTransactionStoreManager.java	45.99% <0%> (-1.05%)	19% <0%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 98cd83b...826ec76. Read the comment docs.

[xingfudeshi]

Good!LGTM.

[xingfudeshi]

@BeiKeJieDeLiuLangMao You need to re-push these commits.

[xingfudeshi]

Because you've just associated your github account with email.

[slievrly]

LGTM