announce port=1025 instead of port=1, when there is no listen port

[Aurumh4x]

slight update from #4400

this was causing issues with certain trackers which block advertised listen ports less than 1024 - HDInnovations/UNIT3D-Community-Edition#3329

this was causing bugs with using libtorrent based clients (such as qbittorrent) when using socks proxy, as seen in following issues
HDInnovations/UNIT3D-Community-Edition#3428
HDInnovations/UNIT3D-Community-Edition#3847

please let me know if there are any other follow on effects from this that might require changes

[MiM-MiM]

This is just quite a terrible idea. Faking a new port rather than fixing the issue will only lead to trackers that liked it blocking these users getting banned. Cheating is not allowed on most sites.

[arvidn]

it does seem like a stretch to do this. Even reporting &port= at all seems wrong. I think it would be more palatable if there would at least be a setting to enable this (or some compatible) behavior.

[ErickBrown]

Makes sense, @arvidn
Rather than announce a default port, why not announce null/nil or simply use the configured listening port (regardless if it's connectable)? An advanced setting option to switch between announcing a default port, no port, or the configured listening port would address the problem as well.
From the UNIT3D perspective, they believe their logic is correct for blocking "faked" ports.