llama2 blog post prompt example contains extra space and new line.

[viniciusarruda]

The system prompt in the llama2 blog post contains an extra space and new line when compared to the original implementation.

[viniciusarruda]

For the ones that are interested. I've implemented a small wrapper around the chat completions fixing that.

[Vaibhavs10]

cc: @osanseviero @philschmid