[TW#26443] Unable to run gen_empty_partition.py with python3

[h1aji]

I am getting this error when I am trying to compile my project:

Traceback (most recent call last):
  File "/home/hmurad/esp/esp-idf/components/app_update/gen_empty_partition.py", line 79, in <module>
    r = main()
  File "/home/hmurad/esp/esp-idf/components/app_update/gen_empty_partition.py", line 70, in main
    generate_blanked_file(size, args.output)
  File "/home/hmurad/esp/esp-idf/components/app_update/gen_empty_partition.py", line 47, in generate_blanked_file
    output += b"\xFF"
TypeError: can only concatenate str (not "bytes") to str

I assume size needs to be bytes instead of str