fix for stacks out of stacking machine (#5020)

code/modules/mining/machine_stacking.dm

@@ -59,6 +59,7 @@
 			var/obj/item/stack/material/S = new stacktype (get_turf(machine.output))
 			S.amount = machine.stack_storage[href_list["release_stack"]]
 			machine.stack_storage[href_list["release_stack"]] = 0
+			S.update_icon()
 
 	src.add_fingerprint(usr)
 	src.updateUsrDialog()
@@ -128,6 +129,7 @@
 			var/obj/item/stack/material/S = new stacktype (get_turf(output))
 			S.amount = stack_amt
 			stack_storage[sheet] -= stack_amt
+			S.update_icon()
 
 	console.updateUsrDialog()
 	return