redirects: Fix parsing BASE_URL with port number (#10350)

The parsing in the redirects module was simply determining the base host
via trimming off everything up to //, so a BASE_URL like
"http://localhost:3000" will result in the host name "localhost:3000",
which isn't a valid host name.

So the problem here is that BASE_URL_HOST is used for determining
whether the client should be redirected and it's comparing the hostname
of the request object with BASE_URL_HOST.

For example if we have the aforementioned BASE_URL, we get to the
following comparison:

req.hostname !== BASE_URL_HOST

Which expands to:

"localhost" !== "localhost:3000"

So in order to get rid of the port number, we now use url.parse() to get
the right host name.

Signed-off-by: aszlig <aszlig@nix.build>

website/server/middlewares/redirects.js

@@ -1,11 +1,11 @@
 import nconf from 'nconf';
+import url from 'url';
 
 const IS_PROD = nconf.get('IS_PROD');
 const IGNORE_REDIRECT = nconf.get('IGNORE_REDIRECT') === 'true';
 const BASE_URL = nconf.get('BASE_URL');
 
-let baseUrlSplit = BASE_URL.split('//');
-const BASE_URL_HOST = baseUrlSplit[1];
+const BASE_URL_HOST = url.parse(BASE_URL).hostname;
 
 function isHTTP (req) {
   return ( // eslint-disable-line no-extra-parens