This is watchdog-client querying watchdog-server.
It's designed to be run by procd before pinging the watchdog.


=== How it works ===
The client queries <URL>/watchdog/<mac>.
When the server responds:
  - 'OK': it exits with status (exit code) 0
  - 'NOT OK': it exits with status 64
  - otherwise (other response, connection failure, etc.): it exits with status 1
