Fix etcdutil2

[lhy1024]

What problem does this PR solve?

Issue Number: Close #xxx

What is changed and how does it work?

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Code changes

• Has the configuration change
• Has HTTP API interfaces changed (Don't forget to add the declarative for the new API)
• Has persistent data change

Side effects

• Possible performance regression
• Increased code complexity
• Breaking backward compatibility

Related changes

• PR to update pingcap/docs/pingcap/docs-cn:
• PR to update pingcap/tiup:
• Need to cherry-pick to the release branch

Release note

None.

[codecov-commenter]

Codecov Report

Merging #34 (00d8112) into master (754095a) will decrease coverage by 0.07%.
Report is 16 commits behind head on master.
The diff coverage is 88.71%.

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Additional details and impacted files

@@            Coverage Diff             @@
##           master      #34      +/-   ##
==========================================
- Coverage   73.77%   73.71%   -0.07%     
==========================================
  Files         429      429              
  Lines       47376    47472      +96     
==========================================
+ Hits        34954    34996      +42     
- Misses       9423     9482      +59     
+ Partials     2999     2994       -5     

Flag	Coverage Δ
unittests	73.71% <88.71%> (-0.07%)	⬇️

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