Remove obsolete `config_backend` option and not required code

The user preferences backend is now always a `db`.

application/controllers/AccountController.php

@@ -69,7 +69,7 @@ class AccountController extends Controller
 
         $form = new PreferenceForm();
         $form->setPreferences($user->getPreferences());
-        if ($config->get('config_backend', 'db') !== 'none' && isset($config->config_resource)) {
+        if (isset($config->config_resource)) {
             $form->setStore(PreferencesStore::create(new ConfigObject(array(
                 'resource'  => $config->config_resource
             )), $user));

application/forms/Config/GeneralConfigForm.php

@@ -37,13 +37,4 @@ class GeneralConfigForm extends ConfigForm
         $this->addSubForm($themingConfigForm->create($formData));
         $this->addSubForm($domainConfigForm->create($formData));
     }
-
-    public function onRequest()
-    {
-        parent::onRequest();
-
-        if ($this->config->get('global', 'config_backend') === 'ini') {
-            $this->warning('The preferences backend of type INI is deprecated and will be removed with version 2.11');
-        }
-    }
 }

library/Icinga/Authentication/Auth.php

@@ -376,7 +376,6 @@ class Auth
             $config = new Config();
         }
 
-        if ($config->get('global', 'config_backend', 'db') !== 'none') {
         $preferencesConfig = new ConfigObject([
             'resource'  => $config->get('global', 'config_resource')
         ]);
@@ -394,9 +393,6 @@ class Auth
             );
             $preferences = new Preferences();
         }
-        } else {
-            $preferences = new Preferences();
-        }
 
         $user->setPreferences($preferences);
 

modules/migrate/library/Migrate/Config/UserDomainMigration.php

@@ -178,34 +178,6 @@ class UserDomainMigration
     {
         $config = Config::app();
 
-        $type = $config->get('global', 'config_backend', 'ini');
-
-        switch ($type) {
-            case 'ini':
-                $directory = Config::resolvePath('preferences');
-
-                $migration = array();
-
-                if (DirectoryIterator::isReadable($directory)) {
-                    foreach (new DirectoryIterator($directory) as $username => $path) {
-                        $user = new User($username);
-
-                        if (! $this->mustMigrate($user)) {
-                            continue;
-                        }
-
-                        $migrated = $this->migrateUser($user);
-
-                        $migration[$path] = dirname($path) . '/' . $migrated->getUsername();
-                    }
-
-                    foreach ($migration as $from => $to) {
-                        rename($from, $to);
-                    }
-                }
-
-                break;
-            case 'db':
         $resourceConfig = ResourceFactory::getResourceConfig($config->get('global', 'config_resource'));
         if ($resourceConfig->db === 'mysql') {
             $resourceConfig->charset = 'utf8mb4';
@@ -253,7 +225,6 @@ class UserDomainMigration
             $conn->getDbAdapter()->commit();
         }
     }
-    }
 
     protected function migrateRoles()
     {

modules/setup/library/Setup/Steps/GeneralConfigStep.php

@@ -28,9 +28,7 @@ class GeneralConfigStep extends Step
             $config[$section][$property] = $value;
         }
 
-        if ($config['global']['config_backend'] === 'db') {
         $config['global']['config_resource'] = $this->data['resourceName'];
-        }
 
         try {
             Config::fromArray($config)
@@ -57,12 +55,7 @@ class GeneralConfigStep extends Step
                 ? t('An exception\'s stacktrace is shown to every user by default.')
                 : t('An exception\'s stacktrace is hidden from every user by default.')
             ) . '</li>'
-            . '<li>' . sprintf(
+            . '<li>' . t('Preferences will be stored using a database.') . '</li>'
-                $this->data['generalConfig']['global_config_backend'] === 'ini' ? sprintf(
-                    t('Preferences will be stored per user account in INI files at: %s'),
-                    Config::resolvePath('preferences')
-                ) : t('Preferences will be stored using a database.')
-            ) . '</li>'
             . '</ul>';
 
         $type = $this->data['generalConfig']['logging_log'];