While this is not a secret and in theory should be in a file under
version control, currently the CONSUL installer disables delayed jobs by
default, meaning we were keeping two versions of the delayed jobs
configuration file, and some existing configurations have their settings
defined in a file in capistrano's `shared` folder.
So we're moving existing settings to the secrets file.
Existing installations having their configuration settings in the
capistrano shared folder needed this migration.
Note we can't just use `YAML.load` because we'd lose the anchors defined
in the file. So we have to parse the file the hard way.