Update youtube-dl to 2020.9.14

[pyup-bot]

This PR updates youtube-dl from 2020.7.28 to 2020.9.14.

Changelog

2020.09.14

Core
+ [postprocessor/embedthumbnail] Add support for non jpg/png thumbnails
(25687, 25717)

Extractors
* [rtlnl] Extend URL regular expression (26549, 25821)
* [youtube] Fix empty description extraction (26575, 26006)
* [srgssr] Extend URL regular expression (26555, 26556, 26578)
* [googledrive] Use redirect URLs for source format (18877, 23919, 24689,
26565)
* [svtplay] Fix id extraction (26576)
* [redbulltv] Improve support for rebull.com TV localized URLs (22063)
+ [redbulltv] Add support for new redbull.com TV URLs (22037, 22063)
* [soundcloud:pagedplaylist] Reduce pagination limit (26557)

2020.09.06

Core
+ [utils] Recognize wav mimetype (26463)

Extractors
* [nrktv:episode] Improve video id extraction (25594, 26369, 26409)
* [youtube] Fix age gate content detection (26100, 26152, 26311, 26384)
* [youtube:user] Extend URL regular expression (26443)
* [xhamster] Improve initials regular expression (26526, 26353)
* [svtplay] Fix video id extraction (26425, 26428, 26438)
* [twitch] Rework extractors (12297, 20414, 20604, 21811, 21812, 22979,
24263, 25010, 25553, 25606)
 * Switch to GraphQL
 + Add support for collections
 + Add support for clips and collections playlists
* [biqle] Improve video ext extraction
* [xhamster] Fix extraction (26157, 26254)
* [xhamster] Extend URL regular expression (25789, 25804, 25927))

Links

• PyPI: https://pypi.org/project/youtube-dl
• Changelog: https://pyup.io/changelogs/youtube-dl/
• Repo: https://github.com/ytdl-org/youtube-dl

Resolves #2318