Update progress time info (#4193)

### What problem does this PR solve?

Ignore the millisecond and microsecond value.

### Type of change

- [x] Refactoring

Signed-off-by: jinhai <haijin.chn@gmail.com>

api/db/services/task_service.py

         if not docs:
             return None
 
-        msg = f"\n{datetime.now().strftime('%H:%M:%S.%f')} Task has been received."
+        msg = f"\n{datetime.now().strftime('%H:%M:%S')} Task has been received."
         prog = random.random() / 10.0
         if docs[0]["retry_count"] >= 3:
             msg = "\nERROR: Task is abandoned after 3 times attempts."

rag/svr/task_executor.py

         if msg:
             msg = f"Page({from_page + 1}~{to_page + 1}): " + msg
     if msg:
-        msg = datetime.now().strftime("%H:%M:%S.%f") + " " + msg
+        msg = datetime.now().strftime("%H:%M:%S") + " " + msg
     d = {"progress_msg": msg}
     if prog is not None:
         d["progress"] = prog