Comment 1 for bug 2044298

Additionally, this also happens if you try to make 2 simultaneous relations to vault, even if you wait until all charms are happy by sleeping for 15 mins first.

```
juju deploy postgresql postgresql --model lxd-cloud/cell0-ovn-central --channel latest/stable --num-units 1
juju deploy vault vault --model lxd-cloud/cell0-ovn-central --config auto-generate-root-ca-cert=true --config totally-unsecure-auto-unlock=true --channel 1.8/stable --num-units 1
juju deploy ovn-central ovn-central --model lxd-cloud/cell0-ovn-central --channel 23.03/stable --num-units 3

# A long 15 minute sleep here

juju integrate ovn-central:certificates vault:certificates --model lxd-cloud/cell0-ovn-central
juju integrate vault:db postgresql:db --model lxd-cloud/cell0-ovn-central
```