Fix GHSA-3qgc-jrrr-25jv

The original code is error-prone due to the "best fit mapping" that
happens with the argument parsing but not with the query string.
When we get a non-ASCII c

Fix GHSA-3qgc-jrrr-25jv

The original code is error-prone due to the "best fit mapping" that
happens with the argument parsing but not with the query string.
When we get a non-ASCII character, try to remap it and see if it becomes
a hyphen.

An alternative approach is to create a custom main `wmain` receiving
wide-character variations that does the ANSI transformation with the
best-fit mapping, but that's more error-prone and could cause unexpected
breakage.

Another alternative was just don't doing this check altogether and
always check for `cgi || fastcgi` instead, but that breaks real-world
use-cases.

show more ...