Update HTTP server example for reactphp/http v1.5.0

Author: clue

theme/homepage.html.twig

@@ -41,7 +41,7 @@
                 <div class="welcome__example">
             {% markdown %}
 ```php
-$server = new React\Http\Server(function (Psr\Http\Message\ServerRequestInterface $request) {
+$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
     return new React\Http\Message\Response(
         200,
         array(
@@ -51,8 +51,8 @@ $server = new React\Http\Server(function (Psr\Http\Message\ServerRequestInterfac
     );
 });
 
-$socket = new React\Socket\Server('127.0.0.1:8080');
-$server->listen($socket);
+$socket = new React\Socket\SocketServer('127.0.0.1:8080');
+$http->listen($socket);
 
 echo "Server running at http://127.0.0.1:8080" . PHP_EOL;
 ```