Wrap missingServerName, update example

examples/ServerName.js

@@ -7,14 +7,22 @@ const app = uWS.SSLApp({
   key_file_name: 'misc/key.pem',
   cert_file_name: 'misc/cert.pem',
   passphrase: '1234'
-}).addServerName("localhost", {
-  key_file_name: 'misc/key.pem',
-  cert_file_name: 'misc/cert.pem',
-  passphrase: '1234'
-}).removeServerName("localhost").addServerName("localhost", {
-  key_file_name: 'misc/key.pem',
-  cert_file_name: 'misc/cert.pem',
-  passphrase: '1234'
+}).missingServerName((hostname) => {
+
+  /* Note: You don't have to use this callback but can pre-load
+   * relevant server names up front. This callback is not "async",
+   * you either add the server name HERE IMMEDIATELY, or the hangshake
+   * will continue with default certificate (which will most likely fail) */
+
+  console.log("Hello! We are missing server name <" + hostname + ">");
+
+  /* We simply assume it is localhost, so adding it here */
+  app.addServerName("localhost", {
+    key_file_name: 'misc/key.pem',
+    cert_file_name: 'misc/cert.pem',
+    passphrase: '1234'
+  });
+
 }).get('/*', (res, req) => {
   res.end('Hello World!');
 }).listen(port, (token) => {