[longomatch] Fix description when duration is null

[Andoni Morales Alastruey <amorales src gnome org>]

commit 91b4f094a404f77c9c25499d76288c0dc4d952f2
Author: Andoni Morales Alastruey <ylatuya gmail com>
Date:   Thu Mar 26 12:45:51 2015 +0100

    Fix description when duration is null

 LongoMatch.Core/Store/Playlists/PlaylistDrawing.cs |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/LongoMatch.Core/Store/Playlists/PlaylistDrawing.cs 
b/LongoMatch.Core/Store/Playlists/PlaylistDrawing.cs
index 302044c..129996b 100644
--- a/LongoMatch.Core/Store/Playlists/PlaylistDrawing.cs
+++ b/LongoMatch.Core/Store/Playlists/PlaylistDrawing.cs
@@ -40,12 +40,12 @@ namespace LongoMatch.Core.Store.Playlists
                        get;
                        set;
                }
-               
+
                public int Height {
                        get;
                        set;
                }
-               
+
                public FrameDrawing Drawing {
                        get;
                        set;
@@ -58,7 +58,7 @@ namespace LongoMatch.Core.Store.Playlists
 
                public string Description {
                        get {
-                               return Duration.ToMSecondsString ();
+                               return Duration == null ? "" : Duration.ToMSecondsString ();
                        }
                }