flag_form_alter clears the content type cache - every call :(

This is fixed in 2, but in 1.3 any call to flag_form_alter calls

    if (count($flags)) {
      $form['flag'] = array(
        '#type' => 'fieldset',
        '#weight' => module_exists('content') ? content_extra_field_weight($form['#node']->type, 'flags') : 1,
        '#tree' => TRUE,
        '#title' => t('Flags'),
        '#collapsible' => TRUE,
      );
    }

This results in a content_clear_type_cache() as there is no "flags" object in the _content_type_info() but there is a "flag" singular.

Patch attached.