[Samba] Enabling LDAPS in Samba in a dual-DC setup

[Stephen]

Hi Rowland. I hear you about the security issues around LDAP.

Unfortunately Redmine is stuck with only LDAP and LDAPS support for now 
- see here. It is an evantual goal for the project to add Kerberos (for 
ten years now...). Only dubious looking third-party plugins with limited 
adoption are available at present to enable Kerberos within Redmine and 
I am loathe to rely upon such implementations.

Thanks

Stephen