Error when getting chat by ID: `more than one found `

Reported by _Blueness Wen_ at https://t.me/c/1083959736/75977.

Message I/O works, but ETM command `/update_info` (which triggers `get_chat()`) fails due to `more than one found` error reported by wxpy.

Initial guess: hashmap collision?

Log:
```
Chat linked (blueset.wechat) is not found in the slave channel (7aab41b2).
Traceback (most recent call last):
File "/usr/lib/python3.8/site-packages/efb_wechat_slave/chats.py", line 162, in search_chat
chat = wxpy.utils.ensure_one(self.bot.search(puid=uid))
File "/usr/lib/python3.8/site-packages/efb_wechat_slave/vendor/wxpy/utils/tools.py", line 42, in ensure_one
raise ValueError('more than one found')
ValueError: more than one found

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/lib/python3.8/site-packages/efb_wechat_slave/chats.py", line 162, in search_chat
chat = wxpy.utils.ensure_one(self.bot.search(puid=uid))
File "/usr/lib/python3.8/site-packages/efb_wechat_slave/vendor/wxpy/utils/tools.py", line 42, in ensure_one
raise ValueError('more than one found')
ValueError: more than one found

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/lib/python3.8/site-packages/efb_telegram_master/chat_binding.py", line 837, in update_group_info
chat = self.chat_manager.update_chat_obj(channel.get_chat(chat_uid), full_update=True)
File "/usr/lib/python3.8/site-packages/efb_wechat_slave/__init__.py", line 704, in get_chat
chat = self.chats.search_chat(uid=chat_uid)
File "/usr/lib/python3.8/site-packages/efb_wechat_slave/chats.py", line 166, in search_chat
return self.search_chat(uid, refresh=True)
File "/usr/lib/python3.8/site-packages/efb_wechat_slave/chats.py", line 168, in search_chat
raise EFBChatNotFound()
ehforwarderbot.exceptions.EFBChatNotFound
```