trimage QT5 support

[Kilian Valkhof <kilian@kilianvalkhof.com>]

Hi,

Trimage is listed under `Apps using python-qt4, bugs not yet filed` on
https://wiki.debian.org/Qt4Removal We've release a new version however,
using python3 and python-qt5:
https://github.com/Kilian/Trimage/releases/tag/1.0.6

Best,

Kilian