Add @jpfr copyright notice to the nodestore.

The automatic assignment was lost in the git history when the
implementation was moved to the /plugins folder.

plugins/ua_nodestore_default.c

@@ -1,6 +1,7 @@
 /* This work is licensed under a Creative Commons CCZero 1.0 Universal License.
  * See http://creativecommons.org/publicdomain/zero/1.0/ for more information. 
  *
+ *    Copyright 2014-2017 (c) Fraunhofer IOSB (Author: Julius Pfrommer)
  *    Copyright 2017 (c) Julian Grothoff
  *    Copyright 2017 (c) Stefan Profanter, fortiss GmbH
  */

plugins/ua_nodestore_default.h

@@ -1,6 +1,7 @@
 /* This work is licensed under a Creative Commons CCZero 1.0 Universal License.
  * See http://creativecommons.org/publicdomain/zero/1.0/ for more information. 
  *
+ *    Copyright 2014-2017 (c) Fraunhofer IOSB (Author: Julius Pfrommer)
  *    Copyright 2017 (c) Julian Grothoff
  *    Copyright 2017 (c) Stefan Profanter, fortiss GmbH
  */