LDAP DN Mapping was once an array but now it isn't

This is from the Beta days:

"user_dn_mapping":[{"re":"(.+)","template":"uid={0},ou=People,dc=openldap,dc=default,dc=svc"}] 

Now it is just a map with 'regex' removed.

"userDNMapping":{"template":"uid=%u,ou=People,dc=openldap,dc=default,dc=svc"}

I checked ns_server code and the underlying type is still an array - which suggests it's just the external interface that has changed...ie ui -> ns_server.

     {user_dn_mapping, {'None', []}}, 

*Note also the default is a string which still leads to workarounds in our unmarshalling.

How are we just now seeing this?

The manual ldap login was done back in beta, new tests haven't yet advanced to the point of mapping to ldap users.