fix: gzip plugin schema typo

[bzp2010]

Please answer these questions before submitting a pull request, or your PR will get closed.

Why submit this pull request?

• Bugfix
• New feature provided
• Improve performance
• Backport patches

What changes will this PR take into?

Fix plugin schema of gzip typo, change minItem ot minItems. That broken schema will crash frontend page.

Related issues

fix #2088

Checklist:

• Did you explain what problem does this PR solve? Or what new features have been added?
• Have you added corresponding test cases?
• Have you modified the corresponding document?
• Is this PR backward compatible? If it is not backward compatible, please discuss on the mailing list first

[codecov-commenter]

Codecov Report

Merging #2142 (76734f4) into master (65e2528) will decrease coverage by 14.77%.
The diff coverage is n/a.

❗ Current head 76734f4 differs from pull request most recent head af9c3ea. Consider uploading reports for the commit af9c3ea to get more accurate results

@@             Coverage Diff             @@
##           master    #2142       +/-   ##
===========================================
- Coverage   67.48%   52.70%   -14.78%     
===========================================
  Files         126       38       -88     
  Lines        3294     2935      -359     
  Branches      802        0      -802     
===========================================
- Hits         2223     1547      -676     
- Misses       1071     1194      +123     
- Partials        0      194      +194     

Flag	Coverage Δ
backend-unit-test	52.70% <ø> (?)
frontend-e2e-test	?

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Impacted Files	Coverage Δ
web/src/pages/Upstream/components/Step1.tsx
...mponents/Upstream/components/active-check/Host.tsx
web/src/pages/SSL/service.ts
web/src/pages/Route/components/Step1/MetaView.tsx
web/src/components/Plugin/PluginPage.tsx
web/src/components/Plugin/UI/basic-auth.tsx
web/src/components/RightContent/index.tsx
web/src/components/Upstream/constant.ts
web/src/components/Footer/index.tsx
web/src/app.tsx
... and 154 more

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