Query exceed memory quota can't show ConnID

[wshwsh12]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

tidb> select sum(a) from t group by a;
+--------+
| sum(a) |
+--------+
|   1024 |
+--------+
1 row in set (0.001 sec)

tidb> set @@tidb_mem_quota_query=1;
Query OK, 0 rows affected, 1 warning (0.000 sec)

tidb> select sum(a) from t group by a;
ERROR 8175 (HY000): Your query has been cancelled due to exceeding the allowed memory limit for a single SQL query. Please try narrowing your query scope or increase the tidb_mem_quota_query limit and try again.[conn=0]

2. What did you expect to see? (Required)

See ConnID not equal 0.

3. What did you see instead (Required)

4. What is your TiDB version? (Required)

master

related pr #47063