backup: remove pathnames from progress output

It clutters up the output and isn't super useful

backup.py

@@ -348,7 +348,6 @@ def main(argv: typing.List[str]):
                                     size('orig', 'original_size') +
                                     size('comp', 'compressed_size') +
                                     size('dedup', 'deduplicated_size') +
-                                    f" path={data['path']}" +
                                     "\n").encode()
                         else:
                             continue