API: flip from amsmetadb to ams-pg

[FedericoCeratto]

No description provided.

[hellais]

This looks good to merge!

After we land it, we should also do a bit of a cleanup to remove all references to amsmetadb.ooni.nu by grepping for it.

I found these files containing that reference:

deploy-pipeline.yml
4:- hosts: [datacollector.infra.ooni.io, hkgmetadb.infra.ooni.io, amsmetadb.ooni.nu]
18:- hosts: [hkgmetadb.infra.ooni.io, amsmetadb.ooni.nu]

inventory
45:amsmetadb.ooni.nu
63:amsmetadb.ooni.nu
68:amsmetadb.ooni.nu
106:amsmetadb.ooni.nu
182:amsmetadb.ooni.nu

templates/iptables.filter.part/hkgmetadb.infra.ooni.io
4:-A INPUT -s {{ lookup('dig', 'amsmetadb.ooni.nu/A') }}/32 -p tcp -m tcp --dport 5432 -j ACCEPT

roles/plpsql/templates/recovery.conf
2:primary_slot_name = 'amsmetadb_3'

roles/plpsql/templates/openvpn.active.conf
8:remote {{ lookup('dig', 'amsmetadb.ooni.nu/A') }}

roles/plpsql/templates/pg_hba.conf
97:host replication amsrepl {{ lookup('dig', 'amsmetadb.ooni.nu/A') }}/32 md5