Did you know that openHAB’s apt (and therefore openHABian) and RPM packages come with commands already? They should be on your server too:
Usage: openhab-cli command [options]
backup [filename] -- Stores the current configuration of openHAB.
clean-cache -- Cleans the openHAB temporary folders.
console -- Opens the openHAB console.
info -- Displays distribution information.
reset-ownership -- Gives openHAB control of its own directories.
restore filename -- Restores the openHAB configuration from a backup.
showlogs -- Displays the log messages of openHAB.
start [--debug] -- Starts openHAB in the terminal.
status -- Checks to see if openHAB is running.
stop -- Stops any running instance of openHAB.
That said, the start and restart commands in these scripts do not use the service file, only start a manual instance while hinting that systemctl should be used.