In legacy/trac#17674 and legacy/trac#8976, we block internal addresses when opening a connection. In legacy/trac#18517, we chose 192.0.2.0/24 as a dummy address range for Tor Browser to use for pluggable transports to use when they don't have the actual remote address. Let's add a comment near the IPv4 range in tor_addr_is_internal_ to never block those addresses (or, if we do, to change how Tor Browser and PTs work first).