[depends/ffmpeg] - fix sed (didn't work on osx) - this fixes pkgconfig from ffmpeg configure
[epg] fix implicit std::string constructor with NULL argument
[epg] refactor Update() method into constructor as it's never used elsewhere
Merge pull request #5037 from xhaggi/fix-epg-stdstring-crash

[epg] fix implicit std::string constructor with NULL argument
Merge pull request #5036 from Memphiz/fixffmpegsed

[depends/ffmpeg] - fix sed (didn't work on osx) - this fixes pkgconfig f...
[addons] sync with repo