doc: fix typo in CHANGELOG.md

PR-URL: https://github.com/nodejs/node/pull/12434
Fixes: https://github.com/nodejs/node/issues/12430


Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Brian White <mscdex@mscdex.net>