WIP: Upgrades Jetty 9.4.43.v20210629 to 10.0.15

Correct configuration of websocket compression. Compression is provided out of the box by Jetty's `permessage-deflate` extension.

Previously Openfire was registering the `permessage-deflate` extension, I assume this was attempting to enable websocket compression.

Presently, websocket compression is enabled by default in Jetty. So the correct way to control websocket compression is to disable the `permessage-deflate` extension when compression is not wanted:
jetty/jetty.project#1341

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

@@ -93,8 +93,8 @@ protected void service(HttpServletRequest request, HttpServletResponse response)
     @Override
     public void configure(JettyWebSocketServletFactory factory)
     {
-        if (WebSocketClientConnectionHandler.isCompressionEnabled()) {
-            factory.getAvailableExtensionNames().add("permessage-deflate");
+        if (!WebSocketClientConnectionHandler.isCompressionEnabled()) {
+            factory.getAvailableExtensionNames().remove("permessage-deflate");
         }
         final int messageSize = JiveGlobals.getIntProperty("xmpp.parser.buffer.size", 1048576);
         factory.setInputBufferSize(messageSize * 5);