pam::pamd() $ldap_* parameters removed.
ldap configuration (connection) is done in ldap module,
not handled by this class.
If running on Debian, and pam_ldap => true, symlink
/etc/pam_ldap.conf -> /etc/ldap/ldap.conf is created,
if running on rhel, /etc/ldap.conf -> /etc/openldap/ldap.conf.