Base: Replace the WebSocket demo target URL with a working one

websocket.org was shutdown somewhere in late 2021, switch to
websocket.events to make the demo work.

Base/res/html/misc/websocket.html

@@ -17,7 +17,7 @@
             }
 
             // Websocket echo server, provided from https://www.websocket.org/echo.html
-            var targetUrl = "wss://echo.websocket.org";
+            var targetUrl = "wss://echo.websocket.events";
             var messageContent = "Hello friends :^)";
             println('<span style="color: blue;">Connecting to:</span> ' + targetUrl);
             websocket = new WebSocket(targetUrl);