Make string translatable

Hi,

in revisioning.pages.inc, you have a string that is hardcoded. It should be passed through t() for translations.

Line: 50

if (isset($form['buttons']['delete']) && user_access('delete revisions') && $vid != node_tools_get_current_node_revision_id($nid)) {
      $form['buttons']['delete']['#value'] = 'Delete this revision';
      $form['buttons']['delete']['#submit'][] = '_revisioning_delete_submit';
}

Kind regards