Update copyright header

icinga2.spec

-#/******************************************************************************
-# * Icinga 2                                                                   *
-# * Copyright (C) 2012-2017 Icinga Development Team (https://www.icinga.com/)  *
-# *                                                                            *
-# * This program is free software; you can redistribute it and/or              *
-# * modify it under the terms of the GNU General Public License                *
-# * as published by the Free Software Foundation; either version 2             *
-# * of the License, or (at your option) any later version.                     *
-# *                                                                            *
-# * This program is distributed in the hope that it will be useful,            *
-# * but WITHOUT ANY WARRANTY; without even the implied warranty of             *
-# * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the              *
-# * GNU General Public License for more details.                               *
-# *                                                                            *
-# * You should have received a copy of the GNU General Public License          *
-# * along with this program; if not, write to the Free Software Foundation     *
-# * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.             *
-# ******************************************************************************/
+# Icinga 2 | (c) 2012 Icinga GmbH | GPLv2+
 
 %define revision 2