MFH: r393941
Switch OpenH264 plugin to use environment variable
files/patch-system-openh264 causes patch churn on updates and hits
assertion with DEBUG=on[1]. Rework to use MOZ_GMP_PATH instead.
While here populate Last Updated field to avoid falling back to Epoch start
and disable Automatic Updates in an unlikely case of
- Cisco & Mozilla providing prebuilt version for FreeBSD
- Firefox running with root priveleges i.e., write permission under /usr/local
PR: 202218 [1]
Reported by: kib, pi [1]
Inspired by: Gentoo
Approved by: ports-secteam (feld)