[Uber low priority] Linux 4.17.0 on aarch64

[Riccardo Berto]

Just want to report that I can't add a wg interface of type wireguard 
with linux 4.17.0 on aarch64 (Raspberry Pi 3).

Error message: `RTNETLINK answers: Operation not supported`.

I'm using ArchLinuxARM. Downgrading to 4.16.x makes the issue dissapear. 
This is not high-priority so please Jason, if you're reading this 
message, move this issue further down in your debugging queue as I 
believe almost nobody is using 4.17.0 on aarch64 right now. Maybe 
they'll fix the error by themselves in the coming 4.17.x releases.