fix dynconfig proto usage

Author: Enjection

ydb/draft/dynamic_config.py

@@ -71,7 +71,7 @@ def _get_node_labels_request_factory(node_id):
 
 def _wrap_dynamic_config(config_pb, dynamic_config_cls=None, *args, **kwargs):
     dynamic_config_cls = DynamicConfig if dynamic_config_cls is None else dynamic_config_cls
-    return dynamic_config_cls(config_pb.identity.version, config_pb.identity.cluster, config_pb.config, *args, **kwargs)
+    return dynamic_config_cls(config_pb.identity[0].version, config_pb.identity[0].cluster, config_pb.config[0], *args, **kwargs)
 
 
 def _wrap_get_config_response(rpc_state, response):