missing required credentials message misleading

[Billy Olsen]

When deploying the latest openstack-integrator charm and not supplying the necessary configuration, the status goes into a blocked state, which is good! However, the message presented is slightly misleading:

openstack-integrator wallaby blocked 1 openstack-integrator charmstore stable 140 ubuntu missing required credentials: auth_url, region, username, password, user_domain_name, project_domain_name

It mentions the auth_url, user_domain_name, project_domain_name and such but the actual config options for the charm are hyphen '-' delimited rather than underscore '_' delimited.

Its a bit of a nit, but it'd be more clear if the message presented the name of the charm options.