Fix assert in DIALOG_EESCHEMA_CONFIG when removing many libs at once

eeschema/dialogs/dialog_eeschema_config.cpp

@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2013 Jean-Pierre Charras, jp.charras at wanadoo.fr
- * Copyright (C) 2006-2013 KiCad Developers, see change_log.txt for contributors.
+ * Copyright (C) 2006-2017 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -279,7 +279,7 @@ void DIALOG_EESCHEMA_CONFIG::OnRemoveLibClick( wxCommandEvent& event )
     {
         int pos = selections[selections.GetCount()-1];
 
-        if( pos == (int)m_ListLibr->GetCount() )
+        if( pos >= (int)m_ListLibr->GetCount() )
             pos = m_ListLibr->GetCount() - 1;
 
         m_ListLibr->SetSelection( pos );