Update webui.sh for non-nightly Torch builds

[natefitzgerald]

Description

A simple git clone + ./webui.sh produces the following error on an Arch machine with an AMD Navi 3 (7900XT):

Installing torch and torchvision
Looking in indexes: https://download.pytorch.org/whl/nightly/rocm5.7
Collecting torch
  ERROR: HTTP error 403 while getting https://download.pytorch.org/whl/nightly/rocm5.7/torch-2.2.0.dev20231010%2Brocm5.7-cp310-cp310-linux_x86_64.whl (from https://download.pytorch.org/whl/nightly/rocm5.7/torch/)
ERROR: Could not install requirement torch

I think Torch moved the url for their Nightly builds or something, I don't know. Regardless, this fixes the error on my machine and allows the installation to proceed.

Checklist:

• I have read contributing wiki page
• I have performed a self-review of my own code
• My code follows the style guidelines
• My code passes tests