set_light() via update() will now accept null values via maxed color

Created by: Intigracy

see comments if the title is confusing

If you take a colored light bulb and put it in a socket, and then try putting in a bulb with a null color (aka almost every bulb ever), it will keep the color of the colored one.

this fixes that

There's no functional difference between #FFFFFF and a nulled var except maybe in some checks for updating color, it looks exactly the same otherwise