src: drop localhost6 as allowed host for inspector

CVE-ID: CVE-2021-22884
Refs: https://hackerone.com/bugs?report_id=1069487
PR-URL: https://github.com/nodejs-private/node-private/pull/244


Reviewed-By: Beth Griggs <bgriggs@redhat.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Mary Marchini <oss@mmarchini.me>
Reviewed-By: Michael Dawson <midawson@redhat.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>