streamlink: http://www.euronews.com/live bug

Checklist

• This is a bug report.
• This is a feature request.
• This is a plugin (improvement) request.
• I have read the contribution guidelines.

Description

streamlink-0.6.0-20170525.exe

streamlink.exe http://www.euronews.com/live

[cli][info] Found matching plugin euronews for URL http://www.euronews.com/live
error: Unable to validate JSON: Unable to validate key 'backup': Type of 'http://euronews-fr-b7-cdn.hexaglobe.net/408a8175f58832bfce904f010908c600/5927fd60/euro
news/euronews-euronews-website-web-responsive-2/ewnsabrfrpri_fre.smil/playlist.m3u8' should be 'dict' but is 'str'

streamlink-0.6.0.exe

streamlink.exe http://www.euronews.com/live

[cli][info] Found matching plugin euronews for URL http://www.euronews.com/live
error: Unable to validate JSON: Unable to validate key 'primary': Type of 'http://euronews-fr-p7-cdn.hexaglobe.net/9e822152542bcfe9a210aada3c14a345/5927fdd7/euronews/euronews-euronews-website-web-responsive-2/ewnsabrfrpri_fre.smil/playlist.m3u8' should be 'dict' but is 'str'

Expected / Actual behavior

This works:

set m3u8=http://euronews-fr-b7-cdn.hexaglobe.net/408a8175f58832bfce904f010908c600/5927fd60/euronews/euronews-euronews-website-web-responsive-2/ewnsabrfrpri_fre.smil/playlist.m3u8 

streamlink hlsvariant://%m3u8% 540p

[cli][info] Found matching plugin stream for URL hlsvariant://http://euronews-fr-b7-cdn.hexaglobe.net/408a8175f58832bfce904f010908c600/5927fd60/euronews/euronews-euronews-website-web-responsive-2/ewnsabrfrpri_fre.smil/playlist.m3u8
[cli][info] Available streams: 90p (worst), 180p, 224p, 360p, 540p, 720p (best)
[cli][info] Opening stream: 540p (hls)
[cli][info] Starting player: C:\P\VLC\vlc.exe

Reproduction steps / Explicit stream URLs to test

1. That m3u8 is french and I try to get english m3u8:

   streamlink --stream-url http://www.euronews.com/live

   error: Unable to validate JSON: Unable to validate key ‘backup’: Type of ‘http://euronews-fr-b7-cdn.hexaglobe.net/3d46191fc31e06a11e8c7d554d20dae5/5928023f/euronews/euronews-euronews-website-web-responsive-2/ewnsabrfrpri_fre.smil/playlist.m3u8’ should be ‘dict’ but is ‘str’

2. http://www.euronews.com/live

   m3u8 with httpfox:

   http://euronews-en-p7-cdn.hexaglobe.net/d5be505f52f37cd9e44016f63d0ce1d0/59280121/euronews/euronews-euronews-website-web-responsive-2/ewnsabrenpri_eng.smil/playlist.m3u8

3. …

Environment details

Operating system and version: win7 64 Streamlink and Python version: …

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Comments, logs, screenshots, etc.

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