[Cin] libav version in About prefs [patch]

[Andrea paz]

In my opinion, it depends on putting the images in /tmp. When I
changed the destination folder (/home/test) I had no more problems.
Try setting up CinGG with a different brender destination folder; one
that is not with root privileges.

PS: I had not responded to this request of yours:
> Are those errors with my patch and normal single-user build, or they only appear in appimage (with my patch?)
All those warnings are from the build with your patches. But the vaapi
decoder works fine.

The vaapi decoder failure errors only affect the appimage (from 2
months ago --> no patch). Those numerous warnings are not present
here, though.