inspector: minor adjustments

Backport-PR-URL: https://github.com/nodejs-private/node-private/pull/109
PR-URL: https://github.com/nodejs-private/node-private/pull/102/


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>