[Enhance][Bug fix] Improve setting file & ...

- Fix a small bug that `best30` of API cannot have scores whose songs are not in database
- At present the setting file can be a module or a file with some of options
- Limiter can have multiple rules together now

latest version/server/multiplayer.py

@@ -1,8 +1,8 @@
+from core.config_manager import Config
 from core.error import ArcError
 from core.linkplay import Player, RemoteMultiPlayer, Room
 from core.sql import Connect
 from flask import Blueprint, request
-from setting import Config
 
 from .auth import auth_required
 from .func import arc_try, success_return