Comment 6 for bug 1638617

Possible workaround:
Edit /var/www/nailgun/plugins/ldap-3.0/deployment_tasks.yaml
 id: ldap_plugin
  type: puppet
  version: 2.0.0
  groups: [primary-controller, controller]
  required_for : [deploy_end]
  requires: [keystone-db, keystone, horizon]
  parameters:
    puppet_manifest: "puppet/manifests/controller_site.pp"
    puppet_modules: "puppet/modules/:/etc/puppet/modules/"
    timeout: 3600

(add "version: 2.0.0" line), save it.
Run plugins sync:
fuel plugins --sync

re-run the upgrade "fuel2 update --env <ENV_ID> install"
upgrade started, I will post the results.