fix(route/youtube): replaceAll undefined when video.description_snippet is empty

[jyungtong]

Involved Issue / 该 PR 相关 Issue

Close #19742

Example for the Proposed Route(s) / 路由地址示例

/youtube/user
/youtube/channel

New RSS Route Checklist / 新 RSS 路由检查表

• New Route / 新的路由
  • Follows Script Standard / 跟随 路由规范
• Anti-bot or rate limit / 反爬/频率限制
  • If yes, do your code reflect this sign? / 如果有, 是否有对应的措施?
• Date and time / 日期和时间
  • Parsed / 可以解析
  • Correct time zone / 时区正确
• New package added / 添加了新的包
• Puppeteer

Note / 说明

[github-actions]

Successfully generated as following:

http://localhost:1200/youtube/user - Failed ❌

HTTPError: Response code 503 (Service Unavailable)

Error Message:<br/>NotFoundError:
Route: /youtube/user
Full Route: /youtube/user
Node Version: v22.18.0
Git Hash: e2b6a690

http://localhost:1200/youtube/channel - Failed ❌

HTTPError: Response code 503 (Service Unavailable)

Error Message:<br/>NotFoundError:
Route: /youtube/channel
Full Route: /youtube/channel
Node Version: v22.18.0
Git Hash: e2b6a690