Updates to pg_hba.conf still restarting postgresql service

/cc @marin @jtevnan

mentioned in issue gitlab-com/infrastructure#2581

Also, ensure that # repmgr is only added to pg_hba.conf if repmgr is adding anything else. Currently it might get added if repmgr is enabled, but with no trusted addresses, and this currently triggers an unnecessary restart. Will check as part of #2714 (closed)

assigned to @ibaum

changed milestone to %9.5

created branch 2713-updates-to-pg_hba-conf-still-restarting-postgresql-service

mentioned in merge request !1878 (merged)

marked this issue as related to #2571

closed via merge request !1878 (merged)