CPVM: fix cpu usage for console vm when using vnc over websockets (#6970)

Co-authored-by: Alexandru Bagu <alexandru.bagu@hotmail.com>

Author: alexandru-bagu

services/console-proxy/server/src/main/java/com/cloud/consoleproxy/ConsoleProxyNoVncClient.java

@@ -114,6 +114,11 @@ public void run() {
                                 updateFrontEndActivityTime();
                             }
                             connectionAlive = client.isVncOverWebSocketConnectionAlive();
+                            try {
+                                Thread.sleep(1);
+                            } catch (Exception e) {
+                                s_logger.warn("Error on sleep for vnc over websocket", e);
+                            }
                         } else if (client.isVncOverNioSocket()) {
                             byte[] bytesArr;
                             int nextBytes = client.getNextBytes();