Fix `TypeError: None has type NoneType, but expected one of: bytes, unicode` in `RunInfo.to_proto` (#6834)
Fix `TypeError: None has type NoneType, but expected one of: bytes, unicode` in `RunInfo.to_proto` (#6834)

* Fix RunInfo.to_proto

Signed-off-by: harupy <e7c128a96f7b207246da7c828c67136267e8d868@gmail.com>

* use is not None

Signed-off-by: harupy <e7c128a96f7b207246da7c828c67136267e8d868@gmail.com>

Signed-off-by: harupy <e7c128a96f7b207246da7c828c67136267e8d868@gmail.com>
mlflow/mlflow,mlflow/mlflow,mlflow/mlflow,mlflow/mlflow,mlflow/mlflow,mlflow/mlflow,mlflow/mlflow