fix: cascader missing text

[nagisakon]

Describe the bug
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To Reproduce
Steps to reproduce the behavior:
Version:0.20.0
cascader missing text.

Expected behavior
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Screenshots
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Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
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[wangkailang]

fixed