Allow remote icon types for desktop AppData files
Allow remote icon types for desktop AppData files

If the icon is not redistributable we have to download the icon at runtime.

Fixes: https://github.com/flathub/buildbot-config/issues/9

hughsie/appstream-glib,hughsie/appstream-glib,ximion/appstream-glib,hughsie/appstream-glib,ximion/appstream-glib,ximion/appstream-glib