Steps to reproduce

1. Create a ConversationHandler with a ConversationHandler.TIMEOUT state.

2. Add any handler to that state with a callback that has (update: Update, context: CallbackContext) as signature.

3. Watch it fail as (bot, update) are passed along to that callback.

Expected behaviour

When use_context=True is set on the updater, it should call the callback with (update: Update, context: CallbackContext).

Actual behaviour

The callback is called with (bot, update) instead.

Configuration

Operating System:
Any

Version of Python, python-telegram-bot & dependencies:
$ python -m telegram
python-telegram-bot 12.0.0
certifi 2019.06.16
future 0.17.1
Python 3.6.4