Removing pre-shared key from peer using wg set fails

[Jason A. Donenfeld]

Hi Tim,

Thanks for letting me know. This is a tools regression from
0.0.20171111, which I just fixed, based on your report:

https://git.zx2c4.com/WireGuard/patch/?id=7153081da70006a8723474580543bd3223d1baf4

Let me know if this fixes the issue. It will be included in the next snapshot.

Regards,
Jason