Adds busy to flatpack unpacking.

Stops you from spamming the same step to complete a flatpack quickly.

code/modules/research/mechanic/flatpack.dm

@@ -17,6 +17,8 @@
 
 /obj/structure/closet/crate/flatpack/attackby(var/atom/A, mob/user)
 	if(assembling)
+		if(unpacking.assemble_busy)
+			return
 		if(unpacking.action(A, user))
 			return 1
 	if(istype(A, /obj/item/weapon/crowbar) && !assembling)
@@ -57,6 +59,7 @@
 
 /datum/construction/flatpack_unpack
 	steps = list()
+	var/assemble_busy = 0
 
 /datum/construction/flatpack_unpack/New(var/atom/A)
 	var/last_step = ""
@@ -105,10 +108,13 @@
 	var/valid_step = is_right_key(user,used_atom)
 	if(valid_step)
 		if(custom_action(valid_step, used_atom, user))
+			assemble_busy = 1
 			if(do_after(user, 30))
+				assemble_busy = 0
 				var/list/step = steps[steps.len]
 				user << "You successfully [step["action"]] in the assembly."
 				next_step(user)
+			assemble_busy = 0
 			return 1
 	return 0