[empathy] call-window: don't leak the contact

[Guillaume Desmottes <gdesmott src gnome org>]

commit b87990d88e8a9291908d3be694db267835b5ab40
Author: Guillaume Desmottes <guillaume desmottes collabora co uk>
Date:   Thu Feb 23 14:24:37 2012 +0100

    call-window: don't leak the contact

 src/empathy-call-window.c |    5 +----
 1 files changed, 1 insertions(+), 4 deletions(-)
---
diff --git a/src/empathy-call-window.c b/src/empathy-call-window.c
index 97bc583..114ec94 100644
--- a/src/empathy-call-window.c
+++ b/src/empathy-call-window.c
@@ -2370,10 +2370,7 @@ empathy_call_window_dispose (GObject *object)
     g_source_remove (priv->timer_id);
   priv->timer_id = 0;
 
-  if (priv->contact != NULL)
-    {
-      priv->contact = NULL;
-    }
+  tp_clear_object (&priv->contact);
 
   G_OBJECT_CLASS (empathy_call_window_parent_class)->dispose (object);
 }