Fix for failed to load audio error by removing backslashes

[pafitis]

Should change default pathing to avoid use of backslashes \ and instead replace with forward slashes /.

Default behaviour causes downstream read issues with ffmpeg. Error code does not indicate this is the issue.

Either change inp_root = sys.argv[1] in the trainset_preprocess_pipeline_print.py to overwrite backslashes or within my_utils.py