g-i freeze break

[Christoph Reiter <reiter christoph gmail com>]

Hey,

Change in question:
https://gitlab.gnome.org/GNOME/gobject-introspection/merge_requests/142

https://gitlab.gnome.org/GNOME/glib/merge_requests/711 fixes some annotation
on the glib 2.60 stable branch. Since the annotations are handled through
g-i we'd need to update g-i for this to take effect.

ptomato said it would be good to get this in before the freeze:
https://gitlab.gnome.org/GNOME/glib/merge_requests/711#note_455030

azzaronea said it would be regression otherwise:
https://gitlab.gnome.org/GNOME/gobject-introspection/merge_requests/141#note_454532