Configuration is saved even with errors with lemonldap-ng-cli
For example, if you add with CLI combModules key, it will fail if Combination rule is not defined. But the configuration will still be registered.
On the other hand, for Combination, this bug allows to configure it trough CLI, else it is impossible. Indeed, we can not mix "set" and "addKay" with CLI, but Combination requires both to ba valid.
So if we fix this issue, we must lighten the controls on Combination so we can declare it as authentication module without having defining combModules.