fix: 修复在任务为空时访问task_id导致的潜在错误

将task_id和video_url的访问移到任务非空判断之后，避免在任务为空时访问字典键导致的错误

decode_task/decodeTask.py

@@ -42,18 +42,20 @@ def  decode_task_status_handler():
     sql = "SELECT * FROM decode_record WHERE task_status = 0 "
     """json"""
     task = mysql.fetchone(sql)
-    task_id = task['task_id']
-    video_url = task['video_url']
+   
 
     if not task:
         logger.info("任务列表为空")
         return
     else:
+        task_id = task['task_id']
         sql = "UPDATE decode_record SET task_status = 1 WHERE task_id = %s"
         mysql.execute(sql, (task_id,))     
         
         # 获取任务结果
     try:
+        task_id = task['task_id']
+        video_url = task['video_url']
         video_id = task['video_id']
         task_params = {'task_id':task_id, 'video_id':video_id, 'video_url':video_url}
         logger.info(f"task_id = {task_id} , video_id = {video_id}")