the new behavior though causes dyn-dns consumers to be started even before we've learned the IP. that sort of matches the semantics of the module though. not sure the best design yet
although the systemd wantedBy directive is working,
`before` seems to be ignored when the unit fails. so on first run,
dyn-dns runs, fails (poor net connectivity), then trust-dns starts
(fails), then they both restart 10s later.
it's not great, but good enough. also, wan IP is persisted, so this
likely won't happen much in practice.
