pgpool.conf: wd_hostname and more are static text

[k-ta-yamada]

• https://github.com/k-ta-yamada/postgres-ha/blob/master/roles/pool1.rb#L9-L13
• https://github.com/k-ta-yamada/postgres-ha/blob/master/roles/pool2.rb#L9-L13

Change as specified by yaml