[brasero] Silence a warning when exiting without having used an audio project

[Philippe Rouquier <philippr src gnome org>]

commit 9c652de2e135e7a87700c880a5f55c88eb88cbeb
Author: Philippe Rouquier <bonfire-app wanadoo fr>
Date:   Sun Oct 11 20:41:40 2009 +0200

    Silence a warning when exiting without having used an audio project

 src/brasero-audio-disc.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/src/brasero-audio-disc.c b/src/brasero-audio-disc.c
index 9917df1..544e718 100644
--- a/src/brasero-audio-disc.c
+++ b/src/brasero-audio-disc.c
@@ -529,7 +529,8 @@ brasero_audio_disc_reset_real (BraseroAudioDisc *disc)
 		disc->priv->selected_path = NULL;
 	}
 
-	brasero_notify_message_remove (BRASERO_NOTIFY (disc->priv->message), BRASERO_AUDIO_DISC_CONTEXT);
+	if (disc->priv->message)
+		brasero_notify_message_remove (BRASERO_NOTIFY (disc->priv->message), BRASERO_AUDIO_DISC_CONTEXT);
 }
 
 static void