WireGuard doesn't start with activated peer without Public Key

[Hektor]

OPNsense 19.7.10 + 20.1 - just updated.

WireGuard crashes and doesn't start anymore when you add a peer without a public key.

Steps to reproduce:
- Set up WireGuard
- Create a WireGuard peer -> leave the Public Key empty
- Add the peer to the configured WireGuard instance
- Save -> WireGuard seems to crash and will not start anymore until you remove the "empty" peer

Probably it's a WireGuard issue but since I didn't find any logs I'm not sure.

Solution:
- Check if it's a WireGuard issue
- Allow adding valid peers only
- If available: check the WireGuard configuration before applying them and cancel if there's an error

[alfrisch]

I see the same problem running wireguard on OPNsense 20.1.5

As Hektor mentioned there are no Log entries and thus this problem is very difficult to debug.

Running `wireguard-go wg0` on the command line eventually reveals the problem in the wg0.config!

[mimugmail]

WireGuard doesnt log anything, no matter what the problem is. Can you open a Bug Report in GitHub so i dont forget to fix this?

[alfrisch]

I have opened an issue here https://github.com/opnsense/plugins/issues/1850