url: group slashed protocols by protocol name

Reorder slashed protocols so they are grouped by protocol name. This is
done so it doesn't look like we're duplicating protocol names at the
bottom of the list.

PR-URL: #5380
Reviewed-By: Evan Lucas <evanlucas@me.com>

lib/url.js

@@ -48,14 +48,14 @@ const hostlessProtocol = {
 // protocols that always contain a // bit.
 const slashedProtocol = {
   'http': true,
-  'https': true,
-  'ftp': true,
-  'gopher': true,
-  'file': true,
   'http:': true,
+  'https': true,
   'https:': true,
+  'ftp': true,
   'ftp:': true,
+  'gopher': true,
   'gopher:': true,
+  'file': true,
   'file:': true
 };
 const querystring = require('querystring');