Use LLM_MODEL env var in Azure OpenAI function

- Remove model parameter from azure_openai_complete (all LLM complete functions must have the same parameter structure)
- Use LLM_MODEL env var in Azure OpenAI function
- Comment out Lollms example in .env.example (duplication with Ollama example)

.env.example

@@ -13,9 +13,9 @@ LLM_BINDING_HOST=http://host.docker.internal:11434
 LLM_MODEL=mistral-nemo:latest
 
 # Lollms example
-LLM_BINDING=lollms
-LLM_BINDING_HOST=http://host.docker.internal:9600
-LLM_MODEL=mistral-nemo:latest
+# LLM_BINDING=lollms
+# LLM_BINDING_HOST=http://host.docker.internal:9600
+# LLM_MODEL=mistral-nemo:latest
 
 
 # Embedding Configuration (Use valid host. For local services, you can use host.docker.internal)