sandbox nym-mixnode on OpenBSD

[timkuijsten]

These patches pledge(2) and unveil(2) the nym-mixnode daemon so that it can be run with more confidence that it won't disrupt or interfere with other processes running on the same system. Roughly speaking, pledge is like Linux seccomp and unveil can be compared with Landlock.

I know this is a bit of a wild shot, but would the project be interested in incorporating patches like these?