Fix random crash when piston breaks node with no player

mods/HUD/mcl_inventory/creative.lua

@@ -741,7 +741,8 @@ if minetest.is_creative_enabled("") then
 			for _, item in ipairs(drops) do
 				minetest.add_item(pos, item)
 			end
-		end
+		else
+			-- If there is a player
 			local inv = digger:get_inventory()
 			if inv then
 				for _, item in ipairs(drops) do
@@ -752,6 +753,7 @@ if minetest.is_creative_enabled("") then
 			end
 		end
 	end
+end
 
 minetest.register_on_joinplayer(function(player)
 	-- Initialize variables and inventory