[longomatch] Fix excaption seting secondsPerPixel when no timers are loaded

[Andoni Morales Alastruey <amorales src gnome org>]

commit fc8429659c2fba8bbb92eb67230cc23053011a54
Author: Andoni Morales Alastruey <ylatuya gmail com>
Date:   Fri Jun 20 14:27:24 2014 +0200

    Fix excaption seting secondsPerPixel when no timers are loaded

 LongoMatch.Drawing/Widgets/TimersTimeline.cs |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/LongoMatch.Drawing/Widgets/TimersTimeline.cs b/LongoMatch.Drawing/Widgets/TimersTimeline.cs
index 4a4f688..7923591 100644
--- a/LongoMatch.Drawing/Widgets/TimersTimeline.cs
+++ b/LongoMatch.Drawing/Widgets/TimersTimeline.cs
@@ -53,7 +53,11 @@ namespace LongoMatch.Drawing.Widgets
                }
                
                void Update () {
-                       double width = duration.Seconds / SecondsPerPixel;
+                       double width;
+
+                       if (duration == null)
+                               return;
+                       width = duration.Seconds / SecondsPerPixel;
                        widget.Width = width + 10;
                        foreach (TimelineObject tl in timers.Values) {
                                tl.Width = width + 10;