[brasero] Silence a warning

[Philippe Rouquier <philippr src gnome org>]

commit f883e614097e3b2c9c06d681df629bd0e38583bb
Author: Philippe Rouquier <bonfire-app wanadoo fr>
Date:   Tue Aug 18 11:30:04 2009 +0200

    Silence a warning

 src/brasero-video-disc.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/brasero-video-disc.c b/src/brasero-video-disc.c
index d1fed23..e4f7129 100644
--- a/src/brasero-video-disc.c
+++ b/src/brasero-video-disc.c
@@ -1364,6 +1364,9 @@ brasero_video_disc_is_empty (BraseroDisc *disc)
 
 	priv = BRASERO_VIDEO_DISC_PRIVATE (disc);
 	model = gtk_tree_view_get_model (GTK_TREE_VIEW (priv->tree));
+	if (!model)
+		return TRUE;
+
 	return gtk_tree_model_iter_n_children (model, NULL) != 0;
 }