auto resolve archive namespace: fix error

Signed-off-by: mohapatr3 <prasanta.mohapatra@here.com>

Author: mohapatr3

flatdata-py/tests/test_backward_compatibility.py

@@ -32,7 +32,7 @@ def test_instance_reading():
 def test_multi_namespace_instance_reading_implicit():
     root_namespace = None
     archive_name = "Archive"
-    module = Engine(MULTI_NAMESPACE_TEST_SCHEMA).render_python_module(None, archive_name, root_namespace)
+    module, archive_type = Engine(MULTI_NAMESPACE_TEST_SCHEMA).render_python_module(None, archive_name, root_namespace)
     valid_data = {
         "Archive.archive": ARCHIVE_SIGNATURE_PAYLOAD,
         "Archive.archive.schema": module.backward_compatibility_Archive.schema().encode(),