build: add missing ggit-confg.h for introspection
build: add missing ggit-confg.h for introspection

Signed-off-by: Igor Gnatenko <71fb2d16c26f553767b965fdac40e83622cad277@src.gnome.org>

GNOME/libgit2-glib,GNOME/libgit2-glib