[Generic] Better display_id detection

[bato3]

Make sure you are using the latest version: run youtube-dl --version and ensure your version is 2018.07.10. If it's not, read this FAQ entry and update. Issues with outdated version will be rejected.

• I've verified and I assure that I'm running youtube-dl 2018.07.10

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• At least skimmed through the README, most notably the FAQ and BUGS sections
• Searched the bugtracker for similar issues including closed ones
• Checked that provided video/audio/playlist URLs (if any) are alive and playable in a browser

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• Bug report (encountered problems with youtube-dl)
• Site support request (request for adding support for a new site)
• Feature request (request for a new functionality)
• Question
• Other

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youtube-dl.exe -v https://video.sibnet.ru/shell.php?videoid=956371 --get-id
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['-v', 'https://video.sibnet.ru/shell.php?videoid=956371', '--get-id']
[debug] Encodings: locale cp1250, fs mbcs, out cp852, pref cp1250
[debug] youtube-dl version 2018.07.10
[debug] Python version 3.4.4 (CPython) - Windows-10-10.0.17134
[debug] exe versions: ffmpeg 4.0, ffprobe 4.0, phantomjs 2.1.1
[debug] Proxy map: {}
WARNING: Falling back on generic information extractor.
[debug] Default format spec: bestvideo+bestaudio/best
shell

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Description of your issue, suggested solution and other information

Is it possible for YT to return the correct ID: 956371 instead shell?

I did not notice how it is for other generic sites, but if there is no default ID detection from the parameters, then often hidden under id, v, video and f. (IDK, Maybe checking the parameter name regex101: /^((v(ideo)?[-_]?)?(id)?|f)$/)

[dstftw]

video id for generic extractor is nominal.