materio-base-d7/sites/all/modules/contrib/admin/readonlymode/readonlymode.install

<?php 
/**
 * @file
 * Update hook and uninstaller for the Read Only Mode module
 */
 
function readonlymode_uninstall() {
  variable_del('site_readonly');
  variable_del('site_readonly_message');
}

/**
 * Delete old variables
 */
function readonlymode_update_6000() {
  $ret = array();
  variable_del('readonlymode');
  variable_del('readonlymode_path');
  return $ret;
}