[PATCH] contrib: Set addrgenmode to none for WireGuard interfaces.

[Jason A. Donenfeld]

Hey Vittorio,

Thanks for bringing my attention to addrgenmode. At first I tried
fixing this with [1], but this broke tcpdump, so I reverted it with
[2]. Now, thanks to you, we have [3], which hopefully is the correct
way to do things and will be part of the next snapshot if it survives
testing.

Regards,
Jason

[1] https://git.zx2c4.com/WireGuard/commit/?id=9f0db72ffcae21a2c6e965f084873a64fea82958
[2] https://git.zx2c4.com/WireGuard/commit/?id=0311d78316a0544b35705468de1021ff48335142
[3] https://git.zx2c4.com/WireGuard/commit/?id=40b0e8d5b1669cd4be32965a1a60cbb63562512c