chore: only send keep-alive header if not disabled by client

Author: derklaro

web-impl-netty/src/main/java/eu/cloudnetservice/ext/rest/netty/NettyHttpServerHandler.java

@@ -253,7 +253,7 @@ private void handleMessage(
       netty.headers().set(HttpHeaders.DATE, currentDate);
 
       // append the keep-alive information as headers, if needed
-      var keepAlive = !context.closeAfter;
+      var keepAlive = !context.closeAfter && HttpUtil.isKeepAlive(httpRequest);
       HttpUtil.setKeepAlive(netty, keepAlive);
       if (keepAlive) {
         var keepAliveTimeout = NettyHttpServerInitializer.MAX_CONNECTION_IDLE_TIME.toSeconds();