openbsd 7.0 support

[divansantana]

support for openbsd 7.0 would be nice to have.

[dlenski]

I don't use OpenBSD. I don't know what distinguishes OpenBSD's networking configuration utilities from those of other *BSDs. I don't know what distinguishes OpenBSD 7.0 from other releases of OpenBSD.

Pull requests are very welcome. Failing that, explaining what parts of vpn-slice would need modification to work with OpenBSD 7.0 would help.

Most likely, you'd want to start with the FreeBSD support, and figure out what needs changing. (But I might be wrong. Did I mention that I don't know about OpenBSD? 😁)

[divansantana]

I'll see if I can try work on this sometime.