[longomatch] Never show the didactics if there is a single file

[Andoni Morales Alastruey <amorales src gnome org>]

commit 208ddf4349ce498978d4dfdf0d02e2196511dea1
Author: Andoni Morales Alastruey <ylatuya gmail com>
Date:   Mon Mar 23 15:08:38 2015 +0100

    Never show the didactics if there is a single file

 LongoMatch.GUI/Gui/Component/ProjectPeriods.cs |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/LongoMatch.GUI/Gui/Component/ProjectPeriods.cs b/LongoMatch.GUI/Gui/Component/ProjectPeriods.cs
index 274981c..4b3377e 100644
--- a/LongoMatch.GUI/Gui/Component/ProjectPeriods.cs
+++ b/LongoMatch.GUI/Gui/Component/ProjectPeriods.cs
@@ -419,6 +419,9 @@ namespace LongoMatch.Gui.Component
                /// </summary>
                void ShowDidactic (DidacticMessage message)
                {
+                       if (project.Description.FileSet.Count == 1) {
+                               return;
+                       }
                        // Show didactic message, hide secondary player
                        HideSecondaryPlayer ();
                        switch (message) {