It works! 
But I don’t really understand why:
- I tried to change ldap to ldaps into “LDAP server URI” of the account-provider of NS2 (from the server-manager) and I got an error by saving.
- I unbound NS2 from the domain and bound it again. No problem and again ldap into “LDAP server URI”.
- into "/etc/dokuwiki/local.protected.php” of NS2, I replace ldap through ldaps for
$conf[‘plugin’][‘authad’][‘domain_controllers’] =‘ldap://nsdc-NS1.ad.domain.tld’
- restart apache
- and it works!
I’m quite sure that I have tried to replace ldap through ldaps in this file yesterday, but without success.
Today I unbound and re-bound but the parameters are the same => it should have worked yesterday (if I didn’t do a mistake…).
=> IMHO this has just to be modified into the template.
Could somebody confirm or do you @stephdl want to make the modification only based on the info of this topic?
Thanks to have asking the right question!
Bye
Arnaud