[BUG] Issue with bot-in-a-box Gen-AI/Assistant accelerator

**Solution Accelerators**
This repository contains multiple solution accelerators. Please tell us which ones are involved in your report. (Replace the space in between square brackets with an x)
- bot-in-a-box Gen-AI/Assistant accelerator

**Describe the bug**
Tried deploying the solution multiple times following the instructions but the bot doesn't work. I always get the same error message, whatever the prompt I enter.

**To Reproduce**
Steps to reproduce the behavior:
1. Deploy the solution according to the instructions in the repo. Make sure to pick Canada-East region since that is the only region where GPT-4 is available.
2. Go to the Bot service and try "Test WebChat"
3. Enter something in the prompt
4. See error

**Expected behavior**
A valid answer.