pg_log_backend_memory_contexts() and log level

Hi,

pg_log_backend_memory_contexts() should be designed not to send the messages about the memory contexts to the client regardless of client_min_messages. But I found that the message "logging memory contexts of PID %d" can be sent to the client because it's ereport()'d with LOG level instead of LOG_SERVER_ONLY. Is this a bug, and shouldn't we use LOG_SERVER_ONLY level to log that message? Patch attached.

Regards,

-- 
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION