Fix the support of Chinese (Bopomofo)

Originally created by @elouann on #11995 (Redmine)

How to reproduce ?
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Start Tails
Press WinKey + Space
Switch to Chinese (Bopomofo)

Only latin characters appear

(After playing around with different languages, I was able to get it to work, but I’m not able right now to reproduce this workaround)

Related issues

• Related to #11382 (closed)
• Is duplicate of #11292 (closed)