Chinese site show error messages in English

[billmn]

Description

With a site that use Chinese language (zh or any zh-* variation), error messages are in english.

For example, I have created 3 sites: English, Italian and Chinese:

Added the example form in the template from the readme of this repo and submit leaving all fields empty.

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ITALIAN: Submit to http://domain.ext/it show translated error messages in italian 👍

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CHINESE: Submit to http://domain.ext/zh show translated error messages in english ❌

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Steps to reproduce

1. Create a site that use Chinese as language
2. Try to submit using the example form in the readme of this repo, leaving all fields empty

Additional info

• Craft version: 3.5.15.1
• PHP version: 7.4.8
• Contact Form: 2.2.7