SoundCloud: Skip IDs of items that we can't show (NSFW).

Not an ideal way of doing it since there might be thousands of these things, but it should do for now.
SoundCloud: Remove trailing comma.
SoundCloud: Refactor the long if statement.
Merge pull request #263 from duckduckgo/jag/soundcloud-nsfw

SoundCloud: Skip IDs of items that we can't show (NSFW).