feat: add LITELLM_PROXY_HOST to configure address litellm listens on

backend/config.py

@@ -507,3 +507,4 @@ AUDIO_OPENAI_API_KEY = os.getenv("AUDIO_OPENAI_API_KEY", OPENAI_API_KEY)
 LITELLM_PROXY_PORT = int(os.getenv("LITELLM_PROXY_PORT", "14365"))
 if LITELLM_PROXY_PORT < 0 or LITELLM_PROXY_PORT > 65535:
     raise ValueError("Invalid port number for LITELLM_PROXY_PORT")
+LITELLM_PROXY_HOST = os.getenv("LITELLM_PROXY_HOST", "127.0.0.1")