bugfix: fix post method in HttpClientUtil

[LegGasai]

• I have registered the PR changes.

Ⅰ. Describe what this PR did

Ⅱ. Does this pull request fix one issue?

#6834

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

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

This problem is caused by the modification in #6536

[funky-eyes]

LGTM

[funky-eyes]

Error: /home/runner/work/incubator-seata/incubator-seata/common/src/main/java/org/apache/seata/common/util/HttpClientUtil.java:94:17: '}' is not followed by whitespace. [WhitespaceAround]
Error: /home/runner/work/incubator-seata/incubator-seata/common/src/main/java/org/apache/seata/common/util/HttpClientUtil.java:94:18: 'else' is not preceded with whitespace. [WhitespaceAround]

[codecov]

Codecov Report

Attention: Patch coverage is 20.00000% with 4 lines in your changes missing coverage. Please review.

Project coverage is 52.52%. Comparing base (8844ce9) to head (a8797a8).
Report is 1 commits behind head on 2.x.

Files with missing lines	Patch %	Lines
...a/org/apache/seata/common/util/HttpClientUtil.java	20.00%	4 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##                2.x    #6835      +/-   ##
============================================
+ Coverage     52.42%   52.52%   +0.09%     
- Complexity     6378     6388      +10     
============================================
  Files          1080     1080              
  Lines         37560    37565       +5     
  Branches       4452     4453       +1     
============================================
+ Hits          19690    19730      +40     
+ Misses        15921    15885      -36     
- Partials       1949     1950       +1     

Files with missing lines	Coverage Δ
...a/org/apache/seata/common/util/HttpClientUtil.java	36.58% <20.00%> (-1.08%)	⬇️

... and 5 files with indirect coverage changes