Update app.py

app.py

@@ -299,6 +299,9 @@ async def generate_image(
     background_tasks: BackgroundTasks = BackgroundTasks()
 ):
     async def generate_image_task(job_id):
+        global next_id_lock
+        global next_id
+
         try:
             # Save the uploaded image to a temporary file
             temp_image_path = f"/tmp/{job_id}_{image.filename}"