Fixes an exploit with circuit printers

Allows you to print literally anything.

code/modules/integrated_electronics/core/printer.dm

@@ -168,6 +168,8 @@
 		else if(ispath(build_type, /obj/item/integrated_circuit))
 			var/obj/item/integrated_circuit/IC = build_type
 			cost = initial(IC.w_class)
+		else
+			return
 
 		if(metal - cost < 0)
 			to_chat(usr, "<span class='warning'>You need [cost] metal to build that!.</span>")