External Libraries: Update getID3 to version 1.9.20.

A full list of changes in this update can be found on GitHub: https://github.com/JamesHeinrich/getID3/compare/v1.9.19...v1.9.20.

Props hareesh-pillai, desrosj.
Previously [47601-47604].
Fixes #49945.
Built from https://develop.svn.wordpress.org/trunk@48278


git-svn-id: https://core.svn.wordpress.org/trunk@48047 1a063a9b-81f0-0310-95a4-ce76da25c4cd