[gnome-games] Fix missing license header

[Adrien Plazas <aplazas src gnome org>]

commit b47a53546e218b620a3609dced7b1d519de63d2b
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Thu Jun 1 08:49:14 2017 +0200

    Fix missing license header

 src/core/uri-game-factory.vala |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/core/uri-game-factory.vala b/src/core/uri-game-factory.vala
index 1f263f7..7e2e9a7 100644
--- a/src/core/uri-game-factory.vala
+++ b/src/core/uri-game-factory.vala
@@ -1,3 +1,5 @@
+// This file is part of GNOME Games. License: GPL-3.0+.
+
 public interface Games.UriGameFactory : Object {
        public signal void game_added (Game game);