[PATCH] net/bird2: add multicast patch from bird mailing list

[Jason A. Donenfeld]

Hi Olivier,

Great! Thanks for doing that.

Now just waiting for Bernhard to bump wireguard-kmod to the latest,
and we'll have working babel-over-wg again:
https://lists.zx2c4.com/pipermail/wireguard/2021-April/006634.html

Jason