Update rest_lights.cpp
Update rest_lights.cpp

Support `state.ontime` in combination with setting `state.alert` to `lselect` or (for Warning Devices) to `blink`.  The default duration of the warning (300s) or identification (15s) can be overwritten using `state.ontime` (in seconds).
See https://github.com/ebaauw/homebridge-hue/issues/614.

dresden-elektronik/deconz-rest-plugin,dresden-elektronik/deconz-rest-plugin,dresden-elektronik/deconz-rest-plugin,dresden-elektronik/deconz-rest-plugin,dresden-elektronik/deconz-rest-plugin