[rygel] media-engine: Don't crash on missing RTP depayloader

[Jens Georg <jensgeorg src gnome org>]

commit eb25767ce1e5c70804d16492f40c07acede52014
Author: Jens Georg <jensg openismus com>
Date:   Fri Jun 14 22:10:11 2013 +0200

    media-engine: Don't crash on missing RTP depayloader

 src/media-engines/gstreamer/rygel-gst-utils.vala |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/media-engines/gstreamer/rygel-gst-utils.vala 
b/src/media-engines/gstreamer/rygel-gst-utils.vala
index d7b3dd8..af664c1 100644
--- a/src/media-engines/gstreamer/rygel-gst-utils.vala
+++ b/src/media-engines/gstreamer/rygel-gst-utils.vala
@@ -103,6 +103,9 @@ internal abstract class Rygel.GstUtils {
                                                caps,
                                                PadDirection.SINK,
                                                false);
+        if (features == null) {
+            return null;
+        }
 
         // If most "fitting" depayloader was rtpdepay skip it because it is
         // just some kind of proxy.