Potential Fix Livestreams not working

[sirlupusdev]

Hello,

I've found a fix for the live streams not working that's within the scope of this module. ytdl-core apparently doesn't like livestreams and filters mixed together so I added a check that removes the filter when the song duration is null - <Song>.isLive doesn't seem to work anymore (it's always false). If the song is not a livestream, it'll fall back to the default behaviour. Some said that one also has to add isHLS: true when the song's a livestream, however this works for me as is, ytdl probably auto-sets that property.

Please let me know if this is something you can allow.

Relevant issues: https://github.com/fent/node-ytdl-core/issues/839 https://github.com/fent/node-ytdl-core/issues/817