multimedia/plexmediaserver: Update to 1.31.2.6810

ChangeLog: https://forums.plex.tv/t/plex-media-server/30447/563

NEW:

• (TV) Add series- and season-level preferences controlling audio and subtitle stream selection.

FIXES:

• Request to system/agents could fail.
• (CreditsDetection) Scanner might quit unexpectedly in some cases.
• (First Run) Library creation could fail during set up.
• (Playlist) > Smart playlists could fail when set to show/season/artist/album types when requested by someone other than server admin.
• (Push) The server could exit unexpectedly if a database error occurred within certain notification-handling code.
• (Scanner) TV episodes with certain naming formats involving underscores could fail to be scanned in.

PR: 270228
Reported by: b.shertenlieb@yahoo.com (maintainer)