The following setup is working with Apache 2.4.6 authentication against Zentyal 4.1.3
<Location />
AuthType Basic
AuthName "LDAP Credentials Required"
AuthBasicProvider ldap
AuthLDAPURL "ldap://develop.zentyal.local:389/cn=Users,dc=zentyal,dc=local?sAMAccountName?sub?(objectClass=*)"
AuthLDAPBindDN "cn=Administrator,cn=Users,dc=zentyal,dc=local"
AuthLDAPBindPassword "[zentyal.admininstrator.password]"
Require ldap-group "cn=Users,dc=zentyal,dc=local"
</Location>