Update function uses non-existent _system_update_utf8()

When upgrading to 1.0 I got an error about a call to the non-existent function _system_update_utf8(). This function has been removed in Drupal 6 according to api.drupal.org.

From lineage.install:

function lineage_update_1() {
  return _system_update_utf8(array('term_lineage'));
}