Don't double encode GitHub download URLs

[HebaruSan]

Problem

Netkan currently is double-encoding GitHub download URLs, which causes any URL that has an encoded character to fail. See #2401 for details.

Cause

The GitHub API returns the URL already encoded:

• https://api.github.com/repos/jrodrigv/DestructionEffects/releases

        "browser_download_url": "https://github.com/jrodrigv/DestructionEffects/releases/download/v1.8%2C0/DestructionEffects.1.8.0_0412018.zip"

We then encode it again, which changes any % characters to %25, which makes the URL fail with a 404 status:

CKAN/Netkan/Transformers/GithubTransformer.cs

Line 78 in a495f43

json.SafeAdd("download", Uri.EscapeUriString(ghRelease.Download.ToString()));

Changes

The Uri.EscapeUriString call is removed. The DestructionEffects netkan succeeds with this change.

Fixes #2401.

[HebaruSan]

The DestructionEffects author has fixed the problem upstream, but I did test this fix before that:

$ ls -gG
-rw-r--r-- 1 1039 Apr  9 18:15 DestructionEffects-2-v1.8,0.ckan