Use creative.is_enabled_for for creative mode if possible (#1558)

mods/carts/cart_entity.lua

@@ -92,7 +92,8 @@ function cart_entity:on_punch(puncher, time_from_last_punch, tool_capabilities,
 		end
 		-- Pick up cart
 		local inv = puncher:get_inventory()
-		if not minetest.setting_getbool("creative_mode")
+		if not (creative and creative.is_enabled_for
++				and creative.is_enabled_for(puncher:get_player_name()))
 				or not inv:contains_item("main", "carts:cart") then
 			local leftover = inv:add_item("main", "carts:cart")
 			-- If no room in inventory add a replacement cart to the world
@@ -385,7 +386,8 @@ minetest.register_craftitem("carts:cart", {
 		minetest.sound_play({name = "default_place_node_metal", gain = 0.5},
 			{pos = pointed_thing.above})
 
-		if not minetest.setting_getbool("creative_mode") then
+		if not (creative and creative.is_enabled_for
+				and creative.is_enabled_for(placer:get_player_name())) then
 			itemstack:take_item()
 		end
 		return itemstack