chat-template problem with allenai/OLMo-1B-0724-hf

model `allenai/OLMo-1B-0724-hf`doesn't work with vllm-openai server and chat completions due to chat template issue

vllm release: [v0.6.1.post2](https://github.com/vllm-project/vllm/releases/tag/v0.6.1.post2)