makes w_class use defines (#9848)

code/game/objects/items/weapons/storage/toolbox.dm

@@ -14,8 +14,8 @@
 	throwforce = 10
 	throw_speed = 1
 	throw_range = 7
-	w_class = 4
-	max_w_class = 3
+	w_class = ITEMSIZE_LARGE
+	max_w_class = ITEMSIZE_NORMAL
 	max_storage_space = 14 //enough to hold all starting contents
 	origin_tech = list(TECH_COMBAT = 1)
 	attack_verb = list("robusted")
@@ -156,7 +156,7 @@
 	item_state = "lunchbox_rainbow"
 	desc = "A little lunchbox. This one is the colors of the rainbow."
 	attack_verb = list("lunched")
-	w_class = 3
+	w_class = ITEMSIZE_NORMAL
 	max_storage_space = 8
 	var/filled = FALSE