[LightDM] lightdm and sssd with ldap

[François Dagorn]

> Hum, I've also tried to disable sssd and use pam_ldap instead. Unfortunately we are still
> requesting for all the users in our directory  :
>
> - when opening a session
> - but also when CLOSING a session
>
I've tried with XDM, the problem remains the same, so lightdm is not the problem, sorry for
disturb. I've not any idea of what is hapenning ...

-- 
François