A workaround for an apparent bug in Discord.Net's
`SocketGuild.DownloadUsersAsync()` method.
Conclusions made while writing and testing this workaround:
* The guilds it hangs on are seemingly random.
* Guild size does not matter.
* If a download hangs, it never recovers within 2 hours, probably more.
* Trying a guild again never works. It just hangs again.