added module load includes on namespace restriction enforced.

islandora.module

@@ -1634,6 +1634,7 @@ function islandora_datastream_access($op, $datastream, $user = NULL) {
  * Implements hook_islandora_basic_collection_get_query_filters().
  */
 function islandora_islandora_basic_collection_get_query_filters() {
+  module_load_include('inc', 'islandora', 'includes/utilities');
   $enforced = variable_get('islandora_namespace_restriction_enforced', FALSE);
   if ($enforced) {
     $namespace_array = islandora_get_allowed_namespaces();