[gitg] Avoid reloading the navigation panel on dash view

[Ignacio Casal Quinteiro <icq src gnome org>]

commit dd1cfbe7303c69e6e6d7a28acb399a8dd0ada7ce
Author: Techlive Zheng <techlivezheng gmail com>
Date:   Fri May 24 00:52:58 2013 +0800

    Avoid reloading the navigation panel on dash view

 plugins/history/gitg-history-navigation.vala |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/plugins/history/gitg-history-navigation.vala b/plugins/history/gitg-history-navigation.vala
index 5c86a2b..6e4b9e5 100644
--- a/plugins/history/gitg-history-navigation.vala
+++ b/plugins/history/gitg-history-navigation.vala
@@ -100,7 +100,10 @@ namespace GitgHistory
                        set
                        {
                                d_repository = value;
-                               reload();
+                               if (d_repository != null)
+                               {
+                                       reload();
+                               }
                        }
                }