fix(Plugin): add nodelay for limit-req plugin

[Baoyuantop]

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?

According to the latest schema.json, add nodelay options to limit-req plugin.

Related issues

fix #2015

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

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[codecov-commenter]

Codecov Report

Merging #2021 (434ed69) into master (af85591) will increase coverage by 0.06%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2021      +/-   ##
==========================================
+ Coverage   63.52%   63.58%   +0.06%     
==========================================
  Files         121      121              
  Lines        3213     3213              
  Branches      779      779              
==========================================
+ Hits         2041     2043       +2     
+ Misses       1172     1170       -2     

Flag	Coverage Δ
frontend-e2e-test	63.58% <ø> (+0.06%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
web/src/components/Plugin/UI/limit-req.tsx	100.00% <ø> (ø)
web/src/helpers.tsx	72.13% <0.00%> (+3.27%)	⬆️

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[liuxiran]

looking forward to your test case, thanks a lot

[Baoyuantop]

@liuxiran @guoqqqi

[guoqqqi]

LGTM