Avoid moonraker warning on first boot

On first boot, we get this warning, despite the moonraker logs dir being created. I'm guessing it's created after the warning is issued.

```
Unable to create log file at '/var/lib/moonraker/logs/moonraker.log'. Make sure that the folder '/var/lib/moonraker/logs' exists and Moonraker has Read/Write access to the folder. 
```