fix: send correct down signal to socklog, to avoid delay during shutdown

[elratt0r]

When shutting down librenms in docker/podman, socklog hangs until a KILL is issued by s6-init. With this patch it get's send SIGHUP on shutdown instead of SIGTERM. That makes it terminate clean and not hang.

[CLAassistant]

All committers have signed the CLA.