allocate-public-ip model constraint does not survive model migration

[Heather Lanigan]

AllocatePublicIp missing from juju/description package.

$ juju add-model moveme
Added 'moveme' model on serverstack/serverstack with credential 'hml' for user 'admin'
$ juju get-model-constraints

$ juju set-model-constraints "allocate-public-ip=true"
$ juju get-model-constraints
allocate-public-ip=true
$ juju migrate moveme destination
Migration started with ID "4a9a2394-2972-4804-80a3-6706a85dd5c8:0"
$ js
ERROR Model "admin/moveme" has been migrated to controller "destination".
To access it run 'juju switch destination:admin/moveme'.
$ juju switch destination:admin/moveme
serverstack-serverstack:admin/moveme -> destination:admin/moveme
$ juju get-model-constraints

[Heather Lanigan (hmlanigan)]

https://github.com/juju/juju/pull/14244