Fix missing default for LLM env var

Author: robsdedude

docker-compose.yml

@@ -12,7 +12,7 @@ services:
       dockerfile: pull_model.Dockerfile
     environment:
       - OLLAMA_BASE_URL=${OLLAMA_BASE_URL-http://host.docker.internal:11434}
-      - LLM
+      - LLM=${LLM-llama2}
     networks:
       - net