tools: fix header escaping regression

quick fix for #22065

Preferred long term fix can be found at:
https://github.com/nodejs/node/pull/22140

PR-URL: https://github.com/nodejs/node/pull/22084
Fixes: https://github.com/nodejs/node/issues/22065


Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>