corrected default value for logging settings
corrected default value for logging settings

heroku/heroku-buildpack-pgbouncer,BetterWorks/heroku-buildpack-pgbouncer,agriffis/heroku-buildpack-pgbouncer,Yobota/heroku-buildpack-pgbouncer,rmoorman/heroku-buildpack-pgbouncer,realtymaps/heroku-buildpack-pgbouncer