Fix redirect bug when the server runs on a port different from 443

Redirect server previously runned on custom port (default 80) but
redirected always on 443. Now is possible to specify both the http
and https ports for redirect.

Author: daquinoaldo

index.js

@@ -37,13 +37,15 @@ const createServer = () => {
 
   // redirect http to https, usage `app.redirect()`
   app.redirect = function(
-  /* istanbul ignore next: cannot be tested on Travis */ port = 80) {
+    /* istanbul ignore next: cannot be tested on Travis */ httpPort = 80,
+    httpsPort = process.env.PORT || 443) {
     app.http = http.createServer((req, res) => {
       res.writeHead(301, {
-        Location: "https://" + req.headers["host"] + req.url
+        Location: "https://" + req.headers["host"].replace(":" + httpPort, "") +
+          (httpsPort !== 443 ? ":" + httpsPort : "") + req.url
       })
       res.end()
-    }).listen(port)
+    }).listen(httpPort)
     console.info("http to https redirection active.")
   }
 
@@ -94,7 +96,7 @@ process.on("uncaughtException", function(err) {
       break
     case "EADDRINUSE":
       console.error("EADDRINUSE: another service on your machine is using " +
-      "port 443 or port 80.\nStop it or change port with:" +
+      "the current port.\nStop it or change port with:" +
       "`PORT=4433 serve ~/myproj`.")
       break
     default: