visualizer IndexError: list index out of range

Hello, i am using this toolkit in win10 with python 3.7.9.

I have downloaded the class Cat and now want to use the virtualizer to view the images.

But i get the following error:

```
Traceback (most recent call last):
File "main.py", line 37, in
bounding_boxes_images(args, DEFAULT_OID_DIR)
File "C:\Users\MS-23\Documents\GitHub\OIDv4_ToolKit\modules\bounding_boxes.py", line 192, in bounding_boxes_images
show(class_name, download_dir, label_dir,len(os.listdir(download_dir))-1, index)
File "C:\Users\MS-23\Documents\GitHub\OIDv4_ToolKit\modules\show.py", line 39, in show
img_file = os.listdir(download_dir)[index]
IndexError: list index out of range
```

Reproduce the visualizer flow from main.py with the downloaded Cat class on Windows 10 and Python 3.7.9. Then inspect modules/bounding_boxes.py at line 192 and modules/show.py at line 39, focusing on the index passed to os.listdir(download_dir). Done means the visualizer opens the downloaded images without an IndexError.

Written by the indexing model from the issue text.