[media.ccc.de] Fix live stream extraction

[TobiGr]

• [x] I carefully read the contribution guidelines and agree to them.
• [x] I have tested the API against NewPipe.
• [x] I agree to create a pull request for NewPipe as soon as possible to make it compatible with the changed API.

The API was slightly changed and only HLS streams are provided anymore.

Add a basic test for to check whether the required streamInfo fields are available.

Fixes #766