Remove deprecated db_and and db_or from hook_query_xmlsitemap_generate_alter example

Hi,

In the hook_query_xmlsitemap_generate_alter example there are references to the deprecated db_and and db_or functions. These should be replaced with the andConditionGroup and orConditionGroup functions.

/**
 * Alter the query selecting data from {xmlsitemap} during sitemap generation.
 *
 * @param $query
 *   A Query object describing the composite parts of a SQL query.
 *
 * @see hook_query_TAG_alter()
 */
function hook_query_xmlsitemap_generate_alter(QueryAlterableInterface $query) {
  $sitemap = $query->getMetaData('sitemap');
  if (!empty($sitemap->context['vocabulary'])) {
    $node_condition = db_and();
    $node_condition->condition('type', 'taxonomy_term');
    $node_condition->condition('subtype', $sitemap->context['vocabulary']);
    $normal_condition = db_and();
    $normal_condition->condition('type', 'taxonomy_term', '<>');
    $condition = db_or();
    $condition->condition($node_condition);
    $condition->condition($normal_condition);
    $query->condition($condition);
  }
}

Cheers

Tom