deconz-rest-plugin: `/lights` resources not available after starting deCONZ

Seems v2.05.73 re-introduced an old bug: after starting deCONZ, the REST API plugin doesn’t expose any /lights resources. It takes a minute or so, before they’re available. I also noticed the GUI stays on the device selection screen for quite some time, and then displays an empty main screen. The nodes only appear after a while.

If homebridge is started before all /lights resources are available, HomeKit removes the lights. If homebridge is restarted, the lights re-appear in HomeKit, but as new lights (losing their HomeKit name and assignments to HomeKit rooms, groups, scenes, and automations). Create a “lightlink” resourcelink, to make homebridge-hue delay homebridge startup until all lights in the resourcelink are available, see https://github.com/ebaauw/homebridge-hue/issues/471.