Bug report: Hardcoded debug logs "pi->node_ids" in pcp_child (v4.7.0)

*Description:* After upgrading to PgPool-II 4.7.0, the logs are being
flooded with internal debug messages every time pcp_proc_info is executed.

*Log Example:* pcp_child pid XXXX: LOG: pi->node_ids[0]:1
pi->node_ids[1]:0. Repeats tens of times.
...
2026-04-06 11:11:03.367: psql pid 188: LOG: pi->node_ids[0]:3
pi->node_ids[1]:0
2026-04-06 11:11:03.367: psql pid 188: LOG: pi->node_ids[0]:3
pi->node_ids[1]:0
2026-04-06 11:11:03.367: psql pid 188: LOG: pi->node_ids[0]:3
pi->node_ids[1]:0
2026-04-06 11:11:03.367: psql pid 188: LOG: pi->node_ids[0]:3
pi->node_ids[1]:0
2026-04-06 11:11:03.367: psql pid 188: LOG: pi->node_ids[0]:3
pi->node_ids[1]:0
2026-04-06 11:11:03.367: psql pid 188: LOG: pi->node_ids[0]:3
pi->node_ids[1]:0
2026-04-06 11:11:03.367: psql pid 188: LOG: pi->node_ids[0]:3
pi->node_ids[1]:0
2026-04-06 11:11:03.367: psql pid 188: LOG: pi->node_ids[0]:3
pi->node_ids[1]:0
2026-04-06 11:11:03.367: psql pid 188: LOG: pi->node_ids[0]:1
pi->node_ids[1]:0
2026-04-06 11:11:03.367: psql pid 188: LOG: pi->node_ids[0]:1
pi->node_ids[1]:0
2026-04-06 11:11:03.367: psql pid 188: LOG: pi->node_ids[0]:3
pi->node_ids[1]:0
2026-04-06 11:11:03.367: psql pid 188: LOG: pi->node_ids[0]:3
pi->node_ids[1]:0
2026-04-06 11:11:03.367: psql pid 188: LOG: pi->node_ids[0]:3
pi->node_ids[1]:0
2026-04-06 11:11:03.367: psql pid 188: LOG: pi->node_ids[0]:3
pi->node_ids[1]:0
2026-04-06 11:11:03.367: psql pid 188: LOG: pi->node_ids[0]:3
pi->node_ids[1]:0
...

*Steps to reproduce:*

1.

Run PgPool-II 4.7.0.
2.

Execute pcp_proc_info.
3.

Check the main PgPool log.

*Current behavior:* Even with log_min_messages = warning and log_pcp_messages
= off, these messages persist. It seems like a hardcoded pool_log or fprintf
in the source code of the PCP child handler.

*Expected behavior:* Internal structure debugging like pi->node_ids should
only appear when debug_level is high or during development builds.

*Environment:*

-

PgPool-II version: 4.7.0
-

OS: Ubuntu (Docker)