Fixes: #528 Possibility to use the pam_check_host_attr feature when using the trust model

contrib/openldap/ldapns.ldif

+dn: cn=ldapns,cn=schema,cn=config
+objectClass: olcSchemaConfig
+cn: cn=ldapns
+# $Id: ldapns.schema,v 1.3 2003/05/29 12:57:29 lukeh Exp $
+# LDAP Name Service Additional Schema
+# http://www.iana.org/assignments/gssapi-service-names
+olcAttributeTypes: ( 1.3.6.1.4.1.5322.17.2.1NAME 'authorizedService' DESC 'IANA GSS-API authorized service name' EQUALITY caseIgnoreMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.15{256} )
+olcObjectClasses: ( 1.3.6.1.4.1.5322.17.1.1NAME 'authorizedServiceObject' DESC 'Auxiliary object class for adding authorizedService attribute' SUP top AUXILIARY MAY authorizedService )
+olcObjectClasses: ( 1.3.6.1.4.1.5322.17.1.2NAME 'hostObject' DESC 'Auxiliary object class for adding host attribute' SUP top AUXILIARY MAY host )