multimedia/svt-hevc: update to 1.4.3
Changes: https://github.com/OpenVisualCloud/SVT-HEVC/releases/tag/v1.4.3
Changes: https://github.com/OpenVisualCloud/SVT-HEVC/compare/v1.4.2...v1.4.3
Reported by: GitHub (watch releases)
MFH: 2019Q4 (regression fix)