Huggingfacve Model with a branch in it's name (seperated by :) can't be used as MODEL Environment variable

[chregu]

If I use for example turboderp/Mixtral-8x7B-instruct-exl2:3.5bpw as MODEL env variable in the template, the script complains about not being able to download it due to invalid characters.

It looks like the scripts/fetch-model.py script doesn't try to parse a branch name and send the appropriate info to scripts/download_model.py, which would support branches with the --branch option

Would be great, if that could be added, so we can automatically download such models, too. My python skills are unfortunately almost non-existent to send a proper PR.

And thanks a lot for for everything.