removes center of mass list (#17064)

* removes center of mass list

* .

* .

* fix that icon

* .

code/modules/materials/sheets/_sheets.dm

@@ -6,7 +6,8 @@
 	w_class = ITEMSIZE_NORMAL
 	throw_speed = 3
 	throw_range = 3
-	center_of_mass = null
+	center_of_mass_x = 0
+	center_of_mass_y = 0
 	max_amount = 50
 	item_icons = list(
 		slot_l_hand_str = 'icons/mob/items/lefthand_material.dmi',
@@ -91,4 +92,4 @@
 	else if(istype(W, /obj/item/stack/rods))
 		material.build_rod_product(user, W, src)
 		return
-	return ..()
+	return ..()