Allow normal m3u rather than m3u8

[brainlessbitch]

Could the ability to use m3u rather than m3u8 be added? it's kinda annoying to have to do mv playlist.m3u8 ./playlist.m3u just so i can play it with mpd, the formats are like exactly the same, just a different extension

[justin025]

I've swapped the extension to m3u in my build here. Alternatively you can build from source, I believe the function you're looking for is in workers/utility.py