fix issue #930

[drafish]

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This is a ...

• New feature
• Bug fix
• Site / document update
• Component style update
• TypeScript definition update
• Refactoring
• Code style optimization
• Branch merge
• Other (about what?)

What's the background?

1. Describe the source of requirement.
   I want to use getFieldDecorator in jsx
2. Resolve what problem.
   FormItem render problem when use getFieldDecorator
3. Related issue link.
   use getFieldDecorator in jsx report an error (TypeError: Cannot read property 'value' of undefined) #930

API Realization (Optional if not new feature)

1. Basic thought of solution and other optional proposal.
2. List final API realization and usage sample.
3. GIF or snapshot should be provided if includes UI/interactive modification.

What's the effect? (Optional if not new feature)

1. Does this PR affect user? Which part will be affected?
2. What will say in changelog?
3. Does this PR contains potential break change or other risk?

Changelog description (Optional if not new feature)

1. English description
2. Chinese description (optional)

Self Check before Merge

• Doc is updated/provided or not needed
• Demo is updated/provided or not needed
• TypeScript definition is updated/provided or not needed
• Changelog is provided or not needed

Additional Plan? (Optional if not new feature)

If this PR related with other PR or following info. You can type here.

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[codecov]

Codecov Report

Merging #931 into master will decrease coverage by 0.01%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master     #931      +/-   ##
==========================================
- Coverage   87.27%   87.25%   -0.02%     
==========================================
  Files         145      145              
  Lines        4817     4818       +1     
  Branches     1421     1422       +1     
==========================================
  Hits         4204     4204              
  Misses        570      570              
- Partials       43       44       +1

Impacted Files	Coverage Δ
components/form/FormItem.jsx	87.12% <0%> (-0.44%)	⬇️

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[github-actions]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.