Add chat_template for tokenizer extracted from GGUF model

[Isotr0py]

What does this PR do?

• Currently, tokenizer extracted from GGUF model misses a chat_template.
• This PR adds missing chat_template through minor fix when extract tokenizer from GGUF model file

Before submitting

• [ ] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• [x] Did you read the contributor guideline, Pull Request section?
• [x] Was this discussed/approved via a Github issue or the forum? Please add a link to it if that's the case.
• [ ] Did you make sure to update the documentation with your changes? Here are the documentation guidelines, and here are tips on formatting docstrings.
• [ ] Did you write any new necessary tests?

Who can review?

Anyone in the community is free to review the PR once the tests have passed. Feel free to tag members/contributors who may be interested in your PR.

@SunMarc