[longomatch] Make sure that Opened returns false after Close.

[Andoni Morales Alastruey <amorales src gnome org>]

commit a043adf7737fa1a3af79754a3bf94718378b0a56
Author: Julien Moutte <julien fluendo com>
Date:   Fri Mar 13 18:48:12 2015 +0100

    Make sure that Opened returns false after Close.

 LongoMatch.GUI.Multimedia/Gui/PlayerBin.cs |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/LongoMatch.GUI.Multimedia/Gui/PlayerBin.cs b/LongoMatch.GUI.Multimedia/Gui/PlayerBin.cs
index eb23d2e..8c0dc73 100644
--- a/LongoMatch.GUI.Multimedia/Gui/PlayerBin.cs
+++ b/LongoMatch.GUI.Multimedia/Gui/PlayerBin.cs
@@ -345,6 +345,7 @@ namespace LongoMatch.Gui
                        ReconfigureTimeout (0);
                        player.Dispose ();
                        blackboard.Dispose ();
+                       fileSet = null;
                }
 
                public void Seek (Time time, bool accurate)