test: add unit test case for func getConflictConfigurations

[whispervince]

Ⅰ. Describe what this PR did

Add unit-test for func getConflictConfigurations

Ⅱ. Does this pull request fix one issue?

Fixes #1759

Ⅲ. Describe how you did it

Implement test cases for different possible scenarios of func getConflictConfigurations

Ⅳ. Describe how to verify it

Run go test under daemon/config/

Ⅴ. Special notes for reviews

Team 10

[pouchrobot]

We found this is your first time to contribute to Pouch, @whispervince
👏 We really appreciate it.
Just remind that you have read the contribution guide: https://github.com/alibaba/pouch/blob/master/CONTRIBUTING.md
If you didn't, you should do that first. If done, welcome again and please enjoy hacking! 🍻

[CLAassistant]

All committers have signed the CLA.

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@afc7a21). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master    #1837   +/-   ##
=========================================
  Coverage          ?   49.78%           
=========================================
  Files             ?      284           
  Lines             ?    18702           
  Branches          ?        0           
=========================================
  Hits              ?     9311           
  Misses            ?     8268           
  Partials          ?     1123

Flag	Coverage Δ
#critest	33.52% <ø> (?)
#integrationtest	37.72% <ø> (?)
#unittest	20.39% <ø> (?)

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