websocketpp: Update WebSocket++ to version 0.7.0

refs #3588

Change-Id: Ief26695554bf0bfff374ba47496aaf9b75f9c630
diff --git a/COPYING.md b/COPYING.md
index 9bbc6fd..373fb0e 100644
--- a/COPYING.md
+++ b/COPYING.md
@@ -14,7 +14,7 @@
 - SQLite is in [public domain](http://www.sqlite.org/copyright.html)
 
 - WebSocket++ library licensed under conditions of
-  [BSD license](https://github.com/zaphoyd/websocketpp/blob/ac5d7ea5af9734de965688b54a7860259887b537/COPYING)
+  [BSD license](https://github.com/zaphoyd/websocketpp/blob/378437aecdcb1dfe62096ffd5d944bf1f640ccc3/COPYING)
 
 - Libpcap library licensed under conditions of
   [a 3-clause BSD license](http://www.tcpdump.org/license.html).