The sleep function does not work when the printer is offline.

[haadamgit]

Describe the bug
The device won't go to sleep when awaiting online printer. Instead it keeps ON unless printer available. The sleep function should work despite device/printer status.

To Reproduce
Steps to reproduce the behavior:

1. Set non zero value for time to sleep on Xtouch
2. turn off power to the printer
3. xtouch looses the connection to the printer (obviously) and while waiting on online printer will never go to sleep.

Expected behavior
The device should ho to sleep even when waiting for online printer or at least there should be a button in settings menu to decide there.

XTOUCH (please complete the following information):

• "version": "0.9.57"

Printers (please complete the following information):

• P1S printer