Check prerequisites for the cURL HTTP Request module

As a part of the solution for #2646894: Redirect http://updates.drupal.org and http://ftp.drupal.org to https version (roll back the updates.drupal.org part?) I tried using this module. Unfortunately it didn't work as the PHP "curl" module is not loaded in my environment.

The following code in chr.install check if the PHP curl module is loaded and refuses to install the module if not.

/**
 * Implements hook_requirements
 */
function chr_requirements($phase) {

  // Check if the PHP curl module is installed

  $requirements= array();
  $t = get_t();

  if ($phase == 'install') {
    if (! function_exists('curl_init')) {
      $requirements['chr'] = array(
        'title' => 'Curl library',
        'description' => 'The cURL HTTP Request module need to have the PHP curl module loaded.',
        'severity' => REQUIREMENT_ERROR,
      );
    }
  }
  return $requirements;
}

A patch will be provided later.

/Thomas