Steps to reproduce

1. pip3 install python-telegram-bot --upgrade
2. Don´t send anything
3. pip3 install python-telegram-bot-4.2.1
4. Works again!

Expected behaviour

Tell us what should happen

Actual behaviour

Tell us what happens instead

Configuration

Operating System:

Version of Python:

$ python -V 3.5

Version of python-telegram-bot:
4.3.2, 4.2.1
$ python -c 'import telegram; print(telegram.__version__)'

Logs

Insert logs here (if necessary)