- `OPENVPN_IPV6` removed
- Affects OpenVPN
- Use the same mechanism for OpenVPN and Wireguard
- Check only once at program start since this is unlikely to change at runtime
- Log if IPv6 is supported
- Remove `IPv6` boolean from settings structs
- Move IPv6 detection as a method on NetLinker
- Fix Slowloris attacks on HTTP servers
- Force set default of 5 minutes for pprof read timeout
- Change `ShutdownTimeout` to time.Duration since it cannot be set to 0
- `HEALTH_TARGET_ADDRESS` to replace `HEALTH_ADDRESS_TO_PING`
- Remove `github.com/go-ping/ping` dependency
- Dial TCP the target address, appending `:443` if port is not set
- Better settings tree structure logged using `qdm12/gotree`
- Read settings from environment variables, then files, then secret files
- Settings methods to default them, merge them and override them
- `DNS_PLAINTEXT_ADDRESS` default changed to `127.0.0.1` to use DoT. Warning added if set to something else.
- `HTTPPROXY_LISTENING_ADDRESS` instead of `HTTPPROXY_PORT` (with retro-compatibility)
