Update copyright year.

git-svn-id: https://svn.apache.org/repos/asf/santuario/xml-security-cpp/trunk@1820991 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/NOTICE.txt b/NOTICE.txt
index 69617c7..f12901e 100644
--- a/NOTICE.txt
+++ b/NOTICE.txt
@@ -1,5 +1,5 @@
 Apache Santuario XML-Security-C Library
-Copyright 2010-2013 The Apache Software Foundation
+Copyright 2010-2018 The Apache Software Foundation
 
 This product includes software developed at
 The Apache Software Foundation (http://www.apache.org/).
@@ -8,4 +8,4 @@
 for use in the OpenSSL Toolkit. (http://www.openssl.org/).
 
 This product also includes software developed, copyrighted, and
-contributed by The Ohio State University.
\ No newline at end of file
+contributed by The Ohio State University.