GH-5040 add the old rdf:type when using legacy vocabulary

Author: hmottestad

core/repository/api/src/main/java/org/eclipse/rdf4j/repository/config/RepositoryConfig.java

@@ -156,6 +156,7 @@ private void exportLegacy(Model model, Resource repositoryNode) {
 		model.setNamespace(RDFS.NS);
 		model.setNamespace(XSD.NS);
 		model.setNamespace("rep", RepositoryConfigSchema.NAMESPACE);
+		model.add(repositoryNode, RDF.TYPE, RepositoryConfigSchema.REPOSITORY);
 
 		if (id != null) {
 			model.add(repositoryNode, RepositoryConfigSchema.REPOSITORYID, literal(id));