added async-supported tag to web.xml

src/main/webapp/WEB-INF/web.xml

@@ -15,6 +15,7 @@
 			<param-name>transports</param-name>
 			<param-value>org.cometd.websocket.server.WebSocketTransport</param-value>
 		</init-param>
+		<async-supported>true</async-supported>
 		<load-on-startup>1</load-on-startup>
 	</servlet>
 	<servlet-mapping>
@@ -42,6 +43,7 @@
 		<filter-class>
 			org.eclipse.jetty.servlets.CrossOriginFilter
 		</filter-class>
+		<async-supported>true</async-supported>
 	</filter>
 	<filter-mapping>
 		<filter-name>