[gnome-builder] flatpak: fix warning from missing cast

[Christian Hergert <chergert src gnome org>]

commit 3ac817581e3cd365dfbff46865cfa19fce388f52
Author: Christian Hergert <chergert redhat com>
Date:   Sun Jun 18 20:50:24 2017 -0700

    flatpak: fix warning from missing cast

 plugins/flatpak/gbp-flatpak-application-addin.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/plugins/flatpak/gbp-flatpak-application-addin.c b/plugins/flatpak/gbp-flatpak-application-addin.c
index faed205..eeb8be8 100644
--- a/plugins/flatpak/gbp-flatpak-application-addin.c
+++ b/plugins/flatpak/gbp-flatpak-application-addin.c
@@ -350,7 +350,7 @@ gbp_flatpak_application_addin_get_runtimes (GbpFlatpakApplicationAddin *self)
           for (guint j = 0; j < ar->len; j++)
             {
               FlatpakInstalledRef *ref = g_ptr_array_index (ar, j);
-              const gchar *name = flatpak_ref_get_name (ref);
+              const gchar *name = flatpak_ref_get_name (FLATPAK_REF (ref));
 
               if (!gbp_flatpak_is_ignored (name))
                 g_ptr_array_add (ret, g_object_ref (ref));