build: notify about the redundancy of "nosign"

vcbuild doesn't sign by default since
92ed1ab4, but there might be people who
haven't noticed the change. This adds a message informing them that
"nosign" is no longer necessary.

PR-URL: https://github.com/nodejs/node/pull/11119


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>