Update push_service: change max pending tasks

pqai_agent/push_service.py

@@ -132,7 +132,7 @@ class PushTaskWorkerPool:
     def process_generate_tasks(self):
         time.sleep(1)
         while True:
-            if self.generate_executor._work_queue.qsize() > self.max_push_workers * 5:
+            if self.generate_executor._work_queue.qsize() > self.max_push_workers * 2:
                 logger.warning("Too many generate tasks in queue, consume later")
                 time.sleep(10)
                 continue