Don't refer to LIGHT_MAX global; use default.

The LIGHT_MAX global is created in the legacy.lua file in the default
mod; it states that it's there for backwards compatibility, but it would
be better to reference the proper value inside the default table.

mesecons_torch/init.lua

@@ -76,7 +76,7 @@ minetest.register_node("mesecons_torch:mesecon_torch_on", {
 	paramtype2 = "wallmounted",
 	selection_box = torch_selectionbox,
 	groups = {dig_immediate=3},
-	light_source = LIGHT_MAX-5,
+	light_source = default.LIGHT_MAX-5,
 	description="Mesecon Torch",
 	mesecons = {receptor = {
 		state = mesecon.state.on,