Add preliminary krb5ExtendedAttributes field to HDB LDIF structure

See https://github.com/heimdal/heimdal/pull/141

confskel/openldap/ldif/hdb.ldif

@@ -29,6 +29,8 @@ olcAttributeTypes: {10}( 1.3.6.1.4.1.5322.10.1.11 NAME 'krb5PrincipalRealm' DE
  SC 'Distinguished name of krb5Realm entry' SUP distinguishedName )
 olcAttributeTypes: {11}( 1.3.6.1.4.1.5322.10.1.12 NAME 'krb5RealmName' EQUALIT
  Y octetStringMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.40{128} )
+olcAttributeTypes: {12}( 1.3.6.1.4.1.5322.10.1.13 NAME 'krb5ExtendedAttributes
+ 'SYNTAX 1.3.6.1.4.1.1466.115.121.1.5 )
 olcObjectClasses: {0}( 1.3.6.1.4.1.5322.10.2.1 NAME 'krb5Principal' SUP top AU
  XILIARY MUST krb5PrincipalName MAY ( cn $ krb5PrincipalRealm ) )
 olcObjectClasses: {1}( 1.3.6.1.4.1.5322.10.2.2 NAME 'krb5KDCEntry' SUP krb5Pri