format changes

includes/utilities.inc

@@ -400,7 +400,7 @@ function islandora_get_datastreams_requirements_from_content_model(FedoraObject
   $xml = new SimpleXMLElement($object[DS_COMP_STREAM]->content);
   foreach ($xml->dsTypeModel as $ds) {
     $dsid = (string) $ds['ID'];
-    $optional = drupal_strtolower((string) $ds['optional']);
+    $optional = strtolower((string) $ds['optional']);
     $mime = array();
     foreach ($ds->form as $form) {
       $mime[] = (string) $form['MIME'];