multimedia/smplayer: update to 20.6.0

Version 20.6

• The internal YouTube code has been removed. Now SMPlayer uses an external application to get the video URLs.
• The shuffle option in the playlist does shuffle the items of the playlist.

Version 20.4.2

• Possibility to enter the opensubtitles.org credentials, which prevents a login error.
• Now it's possible to search for shortcuts in Preferences -> Keyboard.
• Support for mpv 0.32.
• Fix for YouTube.

Changelog:
https://www.smplayer.info/en/changes

PR: 249918
Submitted by: VVD <vvd@unislabs.com> (maintainer)