remove headers timeout hack, rely on nodejs timeouts (#83419)

Author: mshustov

src/core/server/http/http_tools.ts

@@ -103,10 +103,6 @@ interface ListenerOptions {
 export function createServer(serverOptions: ServerOptions, listenerOptions: ListenerOptions) {
   const server = new Server(serverOptions);
 
-  // remove fix + test as soon as update node.js to v12.19 https://github.com/elastic/kibana/pull/61587
-  server.listener.headersTimeout =
-    listenerOptions.keepaliveTimeout + 2 * server.listener.headersTimeout;
-
   server.listener.keepAliveTimeout = listenerOptions.keepaliveTimeout;
   server.listener.setTimeout(listenerOptions.socketTimeout);
   server.listener.on('timeout', (socket) => {

test/server_integration/http/platform/headers.ts

@@ -31,7 +31,7 @@ export default function ({ getService }: FtrProviderContext) {
   const config = getService('config');
 
   describe('headers timeout ', () => {
-    it('issue-73849', async () => {
+    it('handles correctly. See issue #73849', async () => {
       const agent = new Http.Agent({
         keepAlive: true,
       });
@@ -74,7 +74,7 @@ export default function ({ getService }: FtrProviderContext) {
       }
 
       await performRequest();
-      const defaultHeadersTimeout = 40 * oneSec;
+      const defaultHeadersTimeout = 60 * oneSec;
       await delay(defaultHeadersTimeout + oneSec);
       await performRequest();
     });