Add timestamps to llama-server logging

[nialllo]

I find it annoying to check whether a llama-server is active in my home lab.

The latest time stamp in the log isn't visible because it doesn't exist.

In python the logger defaults to time stamps for this reason.

Add time stamps to llama-server output.

Otherwise one must poke around in htop or task manager to try to infer activity.

[ggerganov]

This is already supported - add these to your env:

#export LLAMA_LOG_COLORS=1
export LLAMA_LOG_PREFIX=1
export LLAMA_LOG_TIMESTAMPS=1