Weird periodical pg log

Every single day at exactly the same hour I get this in my pg_log:

< 2017-05-15 17:00:29.517 CEST >FATAL: pg_hba.conf rejects connection
for host "...", user "postgres", database "template1", SSL off
< 2017-05-15 17:00:29.571 CEST >WARNING: archive_mode enabled, yet
archive_command is not set
< 2017-05-15 17:00:41.859 CEST >LOG: received SIGHUP, reloading
configuration files
< 2017-05-15 17:00:41.861 CEST >LOG: parameter "archive_command"
changed to ""/opt/omni/lbin/pgsqlbar.exe" -stage %p -backup"
< 2017-05-15 17:00:51.865 CEST >LOG: received SIGHUP, reloading
configuration files
< 2017-05-15 17:00:51.867 CEST >LOG: parameter "archive_command"
removed from configuration file, reset to default

Postgres 9.5 is running on Centos 7. I checked all cron jobs and
scripts, there is nothing external that would cause this so my guess is
that this is internal Postgres cron job tryin to do "something", I just
don't know what exactly.

We have WAL replication set up, these logs appear on master. Perhaps we
have something off in our conf?

Best regards, cen