ytdl_hook: audio can use fragmented DASH too

Otherwise we'd just use the base URL as media URL, which would fail with
a 404 error.

Not sure if there's a deeper reason why the audio path was explicitly
different from the video one. But this actually works now for a video
that returned fragmented DASH audio with the default format selection.
(This affects streams on that well known site of a big evil Silicon
Valley company. Typically happens after live stream gets converted to a
normal video, though after some time passes, this fragmented version is
deleted, and replaced by a non-fragmented one. I've observed this
several times and this seems to be the "normal" behavior.)

player/lua/ytdl_hook.lua

@@ -318,7 +318,7 @@ local function add_single_video(json)
                 streams[#streams + 1] = edl_track or track.url
             elseif track.acodec and track.acodec ~= "none" and track.vcodec == "none" then
                 -- audio track
-                streams[#streams + 1] = track.url
+                streams[#streams + 1] = edl_track or track.url
             end
         end