Unable to download Wistia video on youtube-dl

[yungsora]

Checklist

• I'm reporting a broken site support issue
• I've verified that I'm running youtube-dl version 2019.12.25
• I've checked that all provided URLs are alive and playable in a browser
• I've checked that all URLs and arguments with special characters are properly quoted or escaped
• I've searched the bugtracker for similar bug reports including closed ones
• I've read bugs section in FAQ

Verbose log

PASTE VERBOSE LOG HERE
```C:\Users\sora>cd downloads

C:\Users\sora\Downloads>cd youtube-dl

C:\Users\sora\Downloads\youtube-dl>youtube-dl -v https://academy.tailoredtutors.co.uk/courses/108779/lectures/1955313
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['-v', 'https://academy.tailoredtutors.co.uk/courses/108779/lectures/1955313']
[debug] Encodings: locale cp1252, fs mbcs, out cp850, pref cp1252
[debug] youtube-dl version 2019.12.25
[debug] Python version 3.4.4 (CPython) - Windows-10-10.0.18362
[debug] exe versions: none
[debug] Proxy map: {}
[generic] 1955313: Requesting header
WARNING: Falling back on generic information extractor.
[generic] 1955313: Downloading webpage
[generic] 1955313: Extracting information
[Teachable] 1955313: Downloading webpage
Traceback (most recent call last):
  File "__main__.py", line 19, in <module>
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp243932xz\build\youtube_dl\__init__.py", line 474, in main
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp243932xz\build\youtube_dl\__init__.py", line 464, in _real_main
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp243932xz\build\youtube_dl\YoutubeDL.py", line 2018, in download
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp243932xz\build\youtube_dl\YoutubeDL.py", line 807, in extract_info
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp243932xz\build\youtube_dl\YoutubeDL.py", line 869, in process_ie_result
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp243932xz\build\youtube_dl\YoutubeDL.py", line 807, in extract_info
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp243932xz\build\youtube_dl\YoutubeDL.py", line 851, in process_ie_result
  File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmp243932xz\build\youtube_dl\utils.py", line 2133, in sanitize_url
AttributeError: 'NoneType' object has no attribute 'startswith'


## Description

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WRITE DESCRIPTION HERE
Unable to download some Wistia videos from an online course. Some videos are able to be downloaded on the playlist but some reasons some aren't even though they seem to be the same format.

[dstftw]

Pass credentials to youtube-dl.