Update packaging to Mono 6.4.0 #17170
This PR updates the compiler and macOS/Linux runtimes from Mono 5.20.1 to 6.4.0. The AppImage runtime also includes a config change
I have tested the runtime changes (but not the specific devtest build) on Ubuntu 18.04, Ubuntu 14.04, CentOS 7, Mint 19.1, MX 18.1 (the same VMs from the original PRs) and macOS without noticing any new regressions.
This doesn't seem to help connecting to e.g. the forum for logging in. I don't see anything in the server list either (e.g. I would expect to see the release and playtest servers). Output when launching from the command line:
The "System.Net.Sockets.SocketOptionName 0x17 is not supported at IP level" line is when trying to load the multiplayer server list.