[folks] Fix build error

[Xavier Claessens <xclaesse src gnome org>]

commit 6947a982cb9855a9f46710a6103f8a24ce1920c1
Author: Xavier Claessens <xavier claessens collabora co uk>
Date:   Wed Sep 5 10:33:19 2012 +0200

    Fix build error

 tests/lib/eds/backend.vala |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/tests/lib/eds/backend.vala b/tests/lib/eds/backend.vala
index f64d9e2..738deea 100644
--- a/tests/lib/eds/backend.vala
+++ b/tests/lib/eds/backend.vala
@@ -276,7 +276,7 @@ public class EdsTest.Backend
 
       try
         {
-          this._source.remove_sync ();
+          this._source.remove_sync (null);
         }
       catch (GLib.Error e)
         {