check_signal_from_dl2.ipynb does not work with mcp v0.4.1

[aaguasca]

The Jupyter notebook check_signal_from_dl2.ipynb does not work because the "get_stereo_events" function in the third code cell has to be updated with the argument "config" in it.

[Elisa-Visentin]

So sorryyyy!!! My fault, I never updated the notebooks after the pipeline upgrades we merged a few months ago. I just opened a new PR to fix it: #213