test : fix mockserverTest fail cause using same port with seata-server

[Bughue]

• [ ] I have registered the PR changes.

Ⅰ. Describe what this PR did

mockserverTest fail cause using same port with seata-server

Ⅱ. Does this pull request fix one issue?

fixes https://github.com/apache/incubator-seata/issues/6320

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

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

[xingfudeshi]

Please register this PR in changes

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (256f0b4) 30.10% compared to head (557e34c) 30.34%. Report is 24 commits behind head on 2.x.

Additional details and impacted files

@@             Coverage Diff              @@
##                2.x    #6325      +/-   ##
============================================
+ Coverage     30.10%   30.34%   +0.24%     
- Complexity     5441     5508      +67     
============================================
  Files           930      936       +6     
  Lines         60222    60249      +27     
  Branches       7121     7088      -33     
============================================
+ Hits          18129    18284     +155     
+ Misses        40204    40041     -163     
- Partials       1889     1924      +35     

see 264 files with indirect coverage changes