double paste removal for delete_user query

      'get_display_name' => 'SELECT name FROM mailbox where username = BINARY :username',

      'set_display_name' => 'UPDATE mailbox SET name = :new_display_name WHERE username = BINARY :username',

      'count_users' => 'SELECT COUNT(*) FROM mailbox',

      'delete_user' => 'SELECT EXISTS(SELECT 1 FROM mailbox WHERE username = :username)',

      //'get_home' => '',

      //'create_user' => '',

    ),

    'hash_algorithm_for_new_passwords' => 'sha512',

  ),