Remove support for config.user, it was broken and bad practise

CHANGELOG.md

@@ -13,6 +13,7 @@
     * Removed an extra `/` in `CompileFile.php` [#1693](https://github.com/getgrav/grav/pull/1693)
     * Uri: Encode user and password to prevent issues in browsers
     * Fixed "Invalid AJAX response" When using Built-in PHP Webserver in Windows [#1258](https://github.com/getgrav/grav-plugin-admin/issues/1258)
+    * Remove support for `config.user`, it was broken and bad practise
     
 # v1.3.8
 ## 10/26/2017

system/src/Grav/Common/User/User.php

@@ -29,7 +29,6 @@ class User extends Data
     {
         $grav = Grav::instance();
         $locator = $grav['locator'];
-        $config = $grav['config'];
 
         // force lowercase of username
         $username = strtolower($username);
@@ -38,7 +37,7 @@ class User extends Data
         $blueprint = $blueprints->get('user/account');
         $file_path = $locator->findResource('account://' . $username . YAML_EXT);
         $file = CompiledYamlFile::instance($file_path);
-        $content = $file->content();
+        $content = (array)$file->content();
         if (!isset($content['username'])) {
             $content['username'] = $username;
         }
@@ -48,9 +47,6 @@ class User extends Data
         $user = new User($content, $blueprint);
         $user->file($file);
 
-        // add user to config
-        $config->set("user", $user);
-
         return $user;
     }