vaultlocker.conf has a hardcoded address as 10.5.0.13 out of the box

[Nobuto Murata]

This is just a wishlist, but it's probably from here:
https://github.com/openstack-charmers/vaultlocker/blob/8edd63e4dc3169268a2b9a868f1f7f1e862da977/etc/vaultlocker.conf

Just after `apt install vaultlocker`, vaultlocker.conf has a hardcoded IP address as 10.5.0.13. It can be a boilerplate instead.

$ cat /etc/vaultlocker/vaultlocker.conf
[vault]
url = http://10.5.0.13:8200
approle = e256bf3b-fb28-b1d6-f2fb-3adc8339d3ad
secret_id = 9428ad25-7b4a-442f-8f20-f23be0575146
backend = secret

# apt policy vaultlocker
vaultlocker:
  Installed: 1.0.6-0ubuntu0.19.10.1~ubuntu18.04.1
  Candidate: 1.0.6-0ubuntu0.19.10.1~ubuntu18.04.1
  Version table:
 *** 1.0.6-0ubuntu0.19.10.1~ubuntu18.04.1 100
        100 http://archive.ubuntu.com/ubuntu bionic-backports/universe amd64 Packages
        100 /var/lib/dpkg/status