RecentChanges.cs: disconnect "note deleted" handler on window close

Fixes #52.

Signed-off-by: Alex Tereschenko <frozen.and.blue@gmail.com>

Tomboy/RecentChanges.cs

@@ -1098,7 +1098,7 @@ void OnDeleteNote (object sender, EventArgs args)
 		void OnCloseWindow (object sender, EventArgs args)
 		{
 			// Disconnect external signal handlers to prevent bloweup
-			manager.NoteDeleted -= OnNotesChanged;
+			manager.NoteDeleted -= OnNotesDeleted;
 			manager.NoteAdded -= OnNotesChanged;
 			manager.NoteRenamed -= OnNoteRenamed;
 			manager.NoteSaved -= OnNoteSaved;