Update inference_test.py

inference_test.py

@@ -76,6 +76,9 @@ def root():
 
 @app.post("/start_chat")
 def start_chat():
+    if llm_model.model is None or llm_model.tokenizer is None:
+        return {"error": "Model yüklenmedi."}
+        
     if not hasattr(app.state, "session_store"):
         app.state.session_store = {}