[soundcloud] Reduce pagination limit to fix 502 Bad Gateway errors when listing a user's tracks.

[tfvlrue]

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Per the documentation here https://developers.soundcloud.com/blog/offset-pagination-deprecated the maximum limit value is actually 200, however 2000 seems to work fine. The exact upper limit I found experimentally was 2847 (anything above the returns a 502 Bad Gateway error). I figured 2000 would provide some leeway in case the actual limit comes down again.

This limit was previously modified by b334732 after many users reported the 502 errors back in May. It seems to have cropped up again, and reducing the limit further seems to fix the problem. @remitamine might be interested in this since they merged in the last fix.

Before:

$ youtube-dl https://soundcloud.com/mediasanctuary
[soundcloud:user] mediasanctuary: Downloading user info
[soundcloud:user] 164222112: Downloading track page 1
ERROR: Unable to download JSON metadata: HTTP Error 502: Bad Gateway (caused by <HTTPError 502: 'Bad Gateway'>); please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; type  youtube-dl -U  to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.

After:

$ youtube-dl https://soundcloud.com/mediasanctuary
[soundcloud:user] mediasanctuary: Downloading user info
[soundcloud:user] 164222112: Downloading track page 1
[soundcloud:user] 164222112: Downloading track page 2
[soundcloud:user] 164222112: Downloading track page 3
[soundcloud:user] 164222112: Downloading track page 4
[download] Downloading playlist: MediaSanctuary (All)
[soundcloud:user] playlist MediaSanctuary (All): Collected 4483 video ids (downloading 4483 of them)
[download] Downloading video 1 of 4483
...

edit: Reduced limit to 200 to match SoundCloud's documentation.

[remitamine]

Add a comment about the limit mentioned in the api documentation and prefix the commit message with [soundcloud].

[tfvlrue]

All set.

[blackjack4494]

good luck @tfvlrue
I gave up that my PRs like this one #26265 will ever be merged. So I am holding back changes on my own fork until there is more activity on here.