OF-1423 Honour configuration for message size

Openfire already uses xmpp.parser.buffer.size as
the maximum stanza size in NIO client sessions.

This change ensures that this is also used when
configuring Websocket sessions.

src/java/org/jivesoftware/openfire/websocket/OpenfireWebSocketServlet.java

@@ -27,6 +27,7 @@ import org.jivesoftware.openfire.SessionManager;
 import org.jivesoftware.openfire.XMPPServer;
 import org.jivesoftware.openfire.session.ClientSession;
 import org.jivesoftware.openfire.session.LocalSession;
+import org.jivesoftware.util.JiveGlobals;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -66,6 +67,9 @@ public class OpenfireWebSocketServlet extends WebSocketServlet {
         if (XmppWebSocket.isCompressionEnabled()) {
             factory.getExtensionFactory().register("permessage-deflate", PerMessageDeflateExtension.class);
         }
+        final int messageSize = JiveGlobals.getIntProperty("xmpp.parser.buffer.size", 1048576);
+        factory.getPolicy().setMaxTextMessageBufferSize(messageSize * 5);
+        factory.getPolicy().setMaxTextMessageSize(messageSize * 5);
         factory.setCreator(new WebSocketCreator() {
             @Override
             public Object createWebSocket(ServletUpgradeRequest req, ServletUpgradeResponse resp)