fixed issue 1

[ljjseu]

Ⅰ. Describe what this PR did

Add unit-test for getConflictConfigurations method which locate on daemon/config/config.go.

Ⅱ. Does this pull request fix one issue?

fixes #1759

Ⅲ. Describe how you did it

Read the function source code and understand the logic of the code，then consider all possibilities

Ⅳ. Describe how to verify it

If the input is equal to the expected output，it means passing the test.

Ⅴ. Special notes for reviews

[pouchrobot]

Thanks for your contribution. 🍻 @ljjseu
While we thought PR TITLE could be more specific, longer than 20 chars.
Please edit this PR title instead of opening a new one.
More details, please refer to https://github.com/alibaba/pouch/blob/master/CONTRIBUTING.md

[CLAassistant]

Thank you for your submission, we really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

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[pouchrobot]

We found this is your first time to contribute to Pouch, @ljjseu
👏 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! 🍻

[pouchrobot]

@ljjseu Thanks for your contribution. 🍻
Please sign off in each of your commits.

[pouchrobot]

ping @ljjseu
Conflict happens after merging a previous commit.
Please rebase the branch against master and push it back again. Thanks a lot.