Compatibiliyt issues between 0.0.20170115 and 0.0.20170517

[Jannis Pinter <jannis@pinterjann.is>]

Hi list,

I use wireguard to connect to my remote LEDE routers which works great
and is really fast. This morning I've upgraded my Arch Linux laptop to
the latest wireguard version and noticed that I can no longer connect to
my routers.

It looks like the handshake between the two devices does not complete. I
can see that my laptop sends UDP packets every 5 seconds to the router,
but the router never sends a packet back.

Downgrading wireguard on my laptop to the previous version 0.0.20170421
solves the issue.

Software versions on LEDE router:
OS: 		LEDE 17.01
Kernel: 	4.4.59
Wireguard:	0.0.20170115

Software versions on my Arch Linux laptop:
OS:		Arch Linux
Kernel:		4.10.13
Wireguard:	0.0.20170517

Now this description is not very detailed, is there anything I could do
to provice more useful debugging output?

Regards,
Jannis