[banshee] gst#: Avoid NRE when AudioCdRipper fails

[Bertrand Lorentz <blorentz src gnome org>]

commit 1126801ed6e079d244294d6ef2a71fbc83f00c73
Author: Bertrand Lorentz <bertrand lorentz gmail com>
Date:   Thu Aug 18 20:57:16 2011 +0200

    gst#: Avoid NRE when AudioCdRipper fails

 .../Banshee.GStreamerSharp/AudioCdRipper.cs        |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/src/Backends/Banshee.GStreamerSharp/Banshee.GStreamerSharp/AudioCdRipper.cs b/src/Backends/Banshee.GStreamerSharp/Banshee.GStreamerSharp/AudioCdRipper.cs
index 132f1e5..da484fc 100644
--- a/src/Backends/Banshee.GStreamerSharp/Banshee.GStreamerSharp/AudioCdRipper.cs
+++ b/src/Backends/Banshee.GStreamerSharp/Banshee.GStreamerSharp/AudioCdRipper.cs
@@ -126,7 +126,9 @@ namespace Banshee.GStreamerSharp
             encoder_pipeline = null;
             output_extension = null;
 
-            timer.Stop ();
+            if (timer != null) {
+                timer.Stop ();
+            }
 
             if (pipeline != null && pipeline is Element) {
                 pipeline.SetState (State.Null);