Update app.py

app.py

@@ -356,7 +356,7 @@ async def process_job(job_id: str, topics_input: Union[str, List[str]], callback
                     response = await client.post(
                         callback_url,
                         json=webhook_data,
-                        headers={"Content-Type": "application/json}
+                        headers={"Content-Type": "application/json"}
                     )
                     
                     logger.info(f"📨 Webhook status: {response.status_code}")