PG HA setup trying to connect to db as gitlab-consul user

/cc @twk3 @jtevnan

created branch 2786-pg-ha-setup-trying-to-connect-to-db-as-gitlab-consul-user

mentioned in merge request !1939 (merged)

mentioned in commit a3964181

closed via merge request !1939 (merged)

mentioned in commit 322e4703

mentioned in issue gitlab-com/infrastructure#2799 (closed)

mentioned in commit 64c44a78

mentioned in commit fe9ed561