Make the systemd service file not require octoprint

[eliasbakken]

With every restart of octoprint, Toggle also restarts.
A better way would be to periodically poll for the presence of octoprint,
in the case that it has not connected.

[eliasbakken]

This is also partly related to Refactor maybe, but for now Toggle is not dependent on OctoPrint. However, if the websocks connection is lost, there is no attempt at reconnecting.