Reset warmup/cooldown when dropping machine pistol

Ideally items should be updateable when not equipped,
then this reset would not be necessary.

src/Dodge/Item/BackgroundEffect.hs

@@ -67,6 +67,8 @@ itEffectOnPickup _ _ = id
 itEffectOnDrop :: Item -> Creature -> World -> World
 itEffectOnDrop itm cr w = case itm ^. itType of
     HELD MINIGUNX{} -> w & pointerToItemID (_itID itm) . itParams . wTime .~ 0
+    HELD MACHINEPISTOL{} -> w & pointerToItemID (_itID itm) . itParams 
+        .~ WarmTime 0 False Nothing
     ITEMSCAN -> cancelExamineInventory w
     HELD FLATSHIELD -> removeShieldWall itm cr w
     _ -> w