Update sys/include/net/gnrc/pktqueue.h

Co-authored-by: crasbe <crasbe@gmail.com>

Author: maribu

sys/include/net/gnrc/pktqueue.h

@@ -1,6 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2014 Martine Lenders <mlenders@inf.fu-berlin.de>
- * SPDX-FileCopyrightText: 2015 Martine Lenders <mlenders@inf.fu-berlin.de>
+ * SPDX-FileCopyrightText: 2014-2015 Martine Lenders <mlenders@inf.fu-berlin.de>
  * SPDX-License-Identifier: LGPL-2.1-only
  */