Fix example on chat_member, fix middleware-exception for async

examples/asynchronous_telebot/chat_member_example.py

@@ -31,4 +31,4 @@ async def my_chat_m(message: types.ChatMemberUpdated):
 async def delall(message: types.Message):
     await bot.delete_message(message.chat.id,message.message_id)
 import asyncio
-asyncio.run(bot.polling())
+asyncio.run(bot.polling(allowed_updates=util.update_types))

telebot/async_telebot.py

@@ -318,7 +318,7 @@ class AsyncTeleBot:
                 except Exception as e:
                     handler_error = e
 
-                    if not middleware:
+                    if not middlewares:
                         if self.exception_handler:
                             return self.exception_handler.handle(e)
                         logging.error(str(e))