Bug: need to specify hash_type='md5' in densenet_training_array.ipynb

Bug
In the densenet_training_array.ipynb under tutorials/3d_regression, the notebook does not run as is. The wrong hash_type is used when download_and_extract is called.

Error
HashCheckError: sha256 hash check of downloaded file failed: url='https://developer.download.nvidia.com/assets/Clara/monai/tutorials/IXI-T1.tar', filepath=PosixPath('/tmp/tmpv5nnnrfy/ixi.tar'), expected sha256=34901a0593b41dd19c1a1f746eac2d58, The file may be corrupted or tampered with. Please retry the download or verify the source.

Fix
The call to download_and_extract(resource, tarfile_name, dataset_dir, md5) should be changed to download_and_extract(resource, tarfile_name, dataset_dir, md5, hash_type='md5') because it expects a 'sha256' by default which would be 64 characters (not 32).

tutorials/3d_regression/densenet_training_array.ipynb を開き、IXI-T1.tar 用の download_and_extract 呼び出しを見つけます。既存の md5 値を使って hash_type='md5' を渡し、その後 notebook またはそのダウンロード手順を実行して、ハッシュチェックが成功することを確認します。