If the YtPlugin already exists on the system, the update check is skpped.

[Hill-98]

I use sccop to install yt-dlp, so let's check it out.

[shinchiro]

Too long commit message. Change to updater: detect installed yt-dlp or youtube-dl on system or something like that

[Obegg]

Now it doesn't check for yt-dlp updates (not even rss feed) + doesn't check for ffmpeg updates.

So if yt-dlp exists = don't update it? what's the reason behind it? I want to update mpv + yt-dlp + ffmpeg.

#35