fix participant page in archiving sample

Author: aoberoi

sample/Archiving/templates/participant.html

@@ -53,7 +53,7 @@ <h3 class="panel-title">Instructions</h3>
         var apiKey = "{{ apiKey }}";
         var token = "{{ token }}";
     </script>
-    <script src="/js/participant.js"></script>
+    <script src="{{ url_for('static', filename='js/participant.js') }}"></script>
 
   </div>