Steam is broken on new kernels

[Pierre-Loup A. Griffais]

This seems to have broken us:

https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.1.11

Here's some affected users:

https://github.com/ValveSoftware/steam-for-linux/issues/6326

https://www.reddit.com/r/linux_gaming/comments/c37lmh/psa_steam_does_not_connect_on_kernels_newer_than/

https://www.phoronix.com/scan.php?page=news_item&px=Steam-Networking-Kernel-Woes

I don't really understand that distributions that claim to be desktop 
products would have fast-tracked a server-oriented fix to all their 
users without testing one of the primary desktop usecases, but that's 
another thing to figure out later.