[Bug] Wrong URL assigned to media if playlist file contains other markers

[porter707]

When parsing a M3U file if it contains any extra markers such as "#EXTGRP" the last URL used is then wrong

For example a file like this

#EXTM3U
#EXTINF:-1 tvg-id="TV1" tvg-name="TV1" tvg-logo="" group-title="TV Group 1",TV 1
#EXTGRP:TV GROUP 1
https://URL1.com
#EXTINF:-1 tvg-id="TV2" tvg-name="TV2" tvg-logo="" group-title="TV Group 2",TV 2
#EXTGRP:TV GROUP 2
https://URL2.com

You end up with the following metadataLine and url:

- "#EXTINF:-1 tvg-id=\"TV1\" tvg-name=\"TV1\" tvg-logo=\"\" group-title=\"TV Group 1\",TV 1"
▿ #EXTGRP:TV%20GROUP%201
  - _url: #EXTGRP:TV%20GROUP%201 #0
    - super: NSObject

- "#EXTINF:-1 tvg-id=\"TV2\" tvg-name=\"TV2\" tvg-logo=\"\" group-title=\"TV Group 2\",TV 2"
▿ https://URL1.com
  - _url: https://URL1.com #0
    - super: NSObject