doc: update LICENSE file

Refs: nodejs#24898

Author: mhamwala

LICENSE

@@ -76,7 +76,7 @@ The externally maintained libraries used by Node.js are:
 
 - c-ares, located at deps/cares, is licensed as follows:
   """
-    Copyright (c) 2007 - 2016, Daniel Stenberg with many contributors, see AUTHORS
+    Copyright (c) 2007 - 2018, Daniel Stenberg with many contributors, see AUTHORS
     file.
 
     Copyright 1998 by the Massachusetts Institute of Technology.