Don't re-damage object with arrow if already dead

mods/ITEMS/mcl_bows/arrow.lua

@@ -184,6 +184,7 @@ ARROW_ENTITY.on_step = function(self, dtime)
 			local is_player = obj:is_player()
 			local lua = obj:get_luaentity()
 			if obj ~= self._shooter and (is_player or (lua and lua._cmi_is_mob)) then
+				if obj:get_hp() > 0 then
 					obj:punch(self.object, 1.0, {
 						full_punch_interval=1.0,
 						damage_groups={fleshy=self._damage},
@@ -207,6 +208,7 @@ ARROW_ENTITY.on_step = function(self, dtime)
 							end
 						end
 					end
+				end
 				self.object:remove()
 				return
 			end