[banshee] [LastfmSource] Fix crash (bgo#612824)

[Alexander Kojevnikov <alexk src gnome org>]

commit 27a024b1314cf516297f2a1c30372f0f0803fb28
Author: Alexander Kojevnikov <alexander kojevnikov com>
Date:   Sun Mar 14 11:17:16 2010 +1100

    [LastfmSource] Fix crash (bgo#612824)

 .../Banshee.Lastfm.Radio/LastfmSource.cs           |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/src/Extensions/Banshee.Lastfm/Banshee.Lastfm.Radio/LastfmSource.cs b/src/Extensions/Banshee.Lastfm/Banshee.Lastfm.Radio/LastfmSource.cs
index 98ac90b..a78385d 100644
--- a/src/Extensions/Banshee.Lastfm/Banshee.Lastfm.Radio/LastfmSource.cs
+++ b/src/Extensions/Banshee.Lastfm/Banshee.Lastfm.Radio/LastfmSource.cs
@@ -341,7 +341,9 @@ namespace Banshee.Lastfm.Radio
                     account.UserName = LastUserSchema.Get ();
                     account.FetchSessionKey ();
                     account.Save ();
-                    LastSessionKeySchema.Set (account.SessionKey);
+                    if (account.SessionKey != null) {
+                        LastSessionKeySchema.Set (account.SessionKey);
+                    }
                 }
 
                 auth_button.Sensitive = refresh_button.Sensitive = NeedAuth;