bug fix for example/localai-webui

[jr19825]

Hi teams,

for example/localai-webui/docker-compose.yaml, there is some issue there,
the newest LocalAI docker image use /models as the models directory, but the docker-compose files in example/localai-webui/docker-compose.yaml actually using /build/models, by the way nothing describe related to .env files, So I suggest don't use it by default, so at least we can start the container.