use .build().start(), since .start() is not working somehow

Author: romain-grecourt

examples/integrations/micrometer/se/src/main/java/io/helidon/examples/micrometer/se/Main.java

@@ -62,6 +62,7 @@ static WebServer startServer() {
         WebServer server = WebServer.builder()
                 .config(config.get("server"))
                 .routing(r -> setupRouting(r, config))
+                .build()
                 .start();
 
         System.out.println("WEB server is up! http://localhost:" + server.port() + "/greet");