Option to mark the power switch as "read-only"
Hi there,

could you please add an option that marks the power-switch of the Fritz!Box device as read-only. I do not need to switch it off remotely and I already pressed the switch once by accident 😛 

I don't know if the HAP specification allows to revoke write-access to the `On` characteristic, but as a workaround you could just ignore the `Set` command in your plugin for this specific power switch.

Best regards