Make placing floor plating on space actually update lighting correctly

code/modules/lighting/light_source.dm

@@ -195,6 +195,11 @@
 
 	effect_str.Cut()
 	effect_turf.Cut()
+	
+/datum/light_source/proc/forget_turf(turf/T)
+	var/idx = effect_turf.Find(T)
+	effect_turf.Cut(idx, idx + 1)
+	effect_str.Cut(idx, idx + 1)
 
 //Smartly updates the lighting, only removes lum from and adds lum to turfs that actually got changed.
 //This is for lights that need to reconsider due to nearby opacity changes.

code/modules/lighting/lighting_turf.dm

@@ -18,3 +18,9 @@
 	if(A.lighting_use_dynamic)
 		var/atom/movable/lighting_overlay/O = new(src)
 		lighting_overlay = O
+		// forcibly refresh lighting on this tile
+		// must make light forget tile or it wil remain
+		// convinced that it is already lighting it
+		for(var/datum/light_source/L in affecting_lights)
+			L.forget_turf(src)
+			L.vis_update()