The source project of this merge request has been removed.
demo: Fix build error in mingw using appstream-glib
Building of appstream items were disable for Windows platform in this commit 9395f52a. But appstream-glib can be built and used in mingw environment. So, appstream_file variable becomes undefined. Hence instead of disabling appstream items for whole Windows system, first check if appstream-util is present then build those.