把 `ConversationHandler` 下的处理过程全部以堵塞方式运行
```
Traceback (most recent call last):
File "/home/luoshuijs/anaconda3/envs/TGPaimonBot/lib/python3.9/site-packages/python_telegram_bot-20.0a0-py3.9.egg/telegram/ext/_application.py", line 929, in process_update
check = handler.check_update(update) # Should the handler handle this update?
File "/home/luoshuijs/anaconda3/envs/TGPaimonBot/lib/python3.9/site-packages/python_telegram_bot-20.0a0-py3.9.egg/telegram/ext/_conversationhandler.py", line 741, in check_update
for candidate in self.states.get(state, []):
TypeError: unhashable type: 'PendingState'
```
目前改BUG已经提交给 `python-telegram-bot` 官方