Use 'unix_socket' instead of 'host' in database config

config/config.default.php

@@ -5,10 +5,10 @@
 return [
     // MySQL-Connection Settings
     'database'                => [
-        'host'     => env('MYSQL_HOST', (env('CI', false) ? 'mariadb' : 'localhost')),
         'database'    => env('MYSQL_DATABASE', 'engelsystem'),
         'username'    => env('MYSQL_USER', 'root'),
         'password'    => env('MYSQL_PASSWORD', ''),
+        'unix_socket' => env('MYSQL_SOCKET', '/var/run/mysqld/mysqld.sock'),
     ],
 
     // For accessing stats