Until now, every connection to the LDAP server was silently unencryptedr
when using Python's ldap module instead of the ldap3 module.
I.e. using Python's ldap module was inherently insecure, as there was not
even a hint that the config settings for encryption were ignored.
This commit changes this and brings LDAP authentication based on the ldap
module feature-wise on par with the one based on the ldap3 module.
2d7a9b001c