fix(amount): fix custom-currency demo disabled

[dyh333]

PR

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• Tests for the changes have been added (for bug fixes / features)
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What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
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• Other... Please describe:

What is the current behavior?

Issue Number: N/A

What is the new behavior?

Does this PR introduce a breaking change?

• Yes
• No

Other information

[kagol]

@all-contributors please add @dyh333 for doc

[allcontributors]

@kagol

I've put up a pull request to add @dyh333! 🎉

[kagol]

@dyh333 恭喜你成为OpenTiny 2023年度开源新星，请添加下OpenTiny小助手微信：opentiny-official，如已添加，请发一条信息给小助手，谢谢！

[Issues-translate-bot]

Bot detected the issue body's language is not English, translate it automatically.

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@dyh333 Congratulations on becoming OpenTiny’s 2023 Open Source Rising Star. Please add the OpenTiny assistant’s WeChat account: opentiny-official. If it has been added, please send a message to the assistant. Thank you!