Explicitly block something like "curl http://10.137.255.254:8082" and
return error page in this case. This error page is used in Whonix to
detect if the proxy is torrified. If not blocked, it may happen that
empty response is returned instead of error. See linked ticket for
details.
FixesQubesOS/qubes-issues#1482
Since this proxy is used only when explicitly configured in application
(package manager), there is no point in worrying about user
_erroneously_ using web browser through this proxy. If the user really
want to access the network from some other application he/she can always
alter firewall rules for that.
FixesQubesOS/qubes-issues#1188
