The lighting queue spreads out the processing of light updates across
multiple ticks based on how much free time the server has left at the end
of the tick.
While the previous logic was logically correct, some CB API's before
would request a chunk without removing it from the unload queue.
While this is logically wrong, some plugins seem to be causing unload issues.
This change will make anything using that one API that use to not remove from
queue, no longer remove from queue.
Hopefully other activities on the server will touch the chunk if it REALLY is in use.
