Fix XSRF token logon to vrtnu

[pgaig]

Please follow the guide below

• You will be asked some questions, please read them carefully and answer honestly
• Put an x into all the boxes [ ] relevant to your pull request (like that [x])
• Use Preview tab to see how your pull request will actually look like

---

Before submitting a pull request make sure you have:

• Searched the bugtracker for similar pull requests
• Read adding new extractor tutorial
• Read youtube-dl coding conventions and adjusted the code to meet them
• Covered the code with tests (note that PRs without tests will be REJECTED)
• Checked the code with flake8

In order to be accepted and merged into youtube-dl each piece of code must be in public domain or released under Unlicense. Check one of the following options:

• I am the original author of this code and I am willing to release it under Unlicense
• I am not the original author of this code but it is in public domain or released under Unlicense (provide reliable evidence)

What is the purpose of your pull request?

• Bug fix
• Improvement
• New extractor
• New feature

---

Description of your pull request and other information

Gets the new required CSRF (aka XSRF) cookie / header to pass the logon of the vrtnu extractor

resolves #29534, resolves #29044

[michaelpeeters]

works for me.

[SamDecrock]

Works for me too. Thanks.

[xplorr]

Works perfect here! Thx!

[BelgianNoise]

Can we get this in the next release ?

[MatthiasCoppens]

Works for me! (Gentoo Linux, Python 3.9)

[pgaig]

Has anyone advice on how to get this fix merged? In the meantime, the forked yt-dlp has this fix incorporated.
Not sure what the next step is (seems to be blocked on 1 workflow awaiting approval -- First-time contributors need a maintainer to approve running workflows).

[xplorr]

I have compiled a windows exe which has this fix merged. If you want, I can send you the link.

[MatthiasCoppens]

I pinged the devs on IRC

[bertvandepoel]

I can also confirm that this works! I'm on Ubuntu 18.04 with Python 3.6.9

[BelgianNoise]

bump, if this even has any effect

[MatthiasCoppens]

At this point I switched to https://github.com/yt-dlp/yt-dlp, it's a shame youtube-dl has gone downhill. yt-dlp is in the AUR for Arch users and in the official repo for Gentoo users.

[BelgianNoise]

Im gonna have grandkids before this gets merged...