fix: transcript results from whisper may have json.language="zh-TW" a…

[shooding]

transcript result from Whisper like:

{
    "transcript": [
        {
            "confidence": 1,
            "text": "大家好"
        }
    ],
    "is_interim": false,
    "language": "zh-TW",
    "message_id": "019368ee-0910-70c8-9b69-15b5d404551d",
    "event": "SPEECH",
    "type": "transcription-result",
    "participant": {
        "avatar_url": "https://www.gravatar.com/avatar/myavatarid?d=wavatar&size=200",
        "name": "韋智Chrome",
        "id": "1721a87f",
        "email": "[email protected]"
    },
    "stability": 1,
    "timestamp": 1732632250201
}

Current code only checks one direction.

[pullrequest]

🔍 This pull request has been sent to HackerOne's PullRequest review team because our automation detected one or more changes with potential security impact or requires further evaluation. Experts are now being assigned to this review based on relevant expertise and will validate or dismiss any security findings accordingly and post their feedback as comments within this pull request.

---

Check the status or cancel this secure code review here.

[jitsi-jenkins]

Hi, thanks for your contribution!
If you haven't already done so, could you please make sure you sign our CLA (https://jitsi.org/icla for individuals and https://jitsi.org/ccla for corporations)? We would unfortunately be unable to merge your patch unless we have that piece :(.

[pullrequest]

✅ Graham C reviewed all the included code changes and associated automation findings and determined that there were no immediately actionable security flaws. Note that they will continue to be notified of any new commits or comments and follow up as needed throughout the duration of this pull request's lifecycle.