fixed handle back ref field in backRef query

SE/se-lib/Api/WfsDataServer.php

@@ -195,7 +195,7 @@ class Api_WfsDataServer extends Api_WfsServerBase {
 			$searchParams['__backRef'] = [
 				'namespace' => $args['backRefNS'],
 				'primaryKey' => $args['backRefPK'],
-				'fieldName' => ($args['backRefField']) ? $args['backRefField'] : $args['typeName'],
+				'fieldName' => ($args['backRefField']) ? $args['backRefField'] : $args['xsd:type'], // $args['typeName'],
 			];
 		}