Fixed background inventory screens not being clickable (#19284)

Fixed background inventory screens not being clickable.
Clicking on a storage item that is already open now closes it.

Fixes #18880

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

@@ -765,7 +765,11 @@
 			return
 
 	if (src.loc == user)
-		src.open(user)
+		//If the storage is already open, close it, otherwise open it
+		if(user.s_active == src)
+			src.close(user)
+		else
+			src.open(user)
 	else
 		..()
 		for(var/mob/M in range(1, get_turf(src)) - user)