Log Message:
youtube-dl: Update to 20190712

Changes:
2019.07.12
----------
Core
+ [adobepass] Add support for AT&T U-verse (mso ATT) (#13938, #21016)

Extractors
+ [mgtv] Pass Referer HTTP header for format URLs (#21726)
+ [beeg] Add support for api/v6 v2 URLs without t argument (#21701)
* [voxmedia:volume] Improvevox embed extraction (#16846)
* [funnyordie] Move extraction to VoxMedia extractor (#16846)
* [gameinformer] Fix extraction (#8895, #15363, #17206)
* [funk] Fix extraction (#17915)
* [packtpub] Relax lesson URL regular expression (#21695)
* [packtpub] Fix extraction (#21268)
* [philharmoniedeparis] Relax URL regular expression (#21672)
* [peertube] Detect embed URLs in generic extraction (#21666)
* [mixer:vod] Relax URL regular expression (#21657, #21658)
+ [lecturio] Add support id based URLs (#21630)
+ [go] Add site info for disneynow (#21613)
* [ted] Restrict info regular expression (#21631)
* [twitch:vod] Actualize m3u8 URL (#21538, #21607)
* [vzaar] Fix videos with empty title (#21606)
* [tvland] Fix extraction (#21384)
* [arte] Clean extractor (#15583, #21614)