test: fix error in test/internet/test-dns.js

Refs: https://github.com/nodejs/node/pull/35466#issuecomment-721936009

PR-URL: https://github.com/nodejs/node/pull/35969


Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>