message: storage: fix error message
diff: @@ -227,7 +227,7 @@ impl<'a> StorageTransaction for S3StorageTransaction<'a> {
  log::error!("error deleting file from s3: {:?}", err);
  }
  - failure::bail!("uploading to s3 failed");
  + failure::bail!("deleting from s3 failed");
  }
  continuation_token = list.continuation_token;
  