Univention Corporate Server 4.3 erratum 159 (bugfix)

This update addresses the following issue(s):
* When operating without a separate VirtualHost for single sign-on, a
  rewrite rule in the scope of other config rules limited execution of
  further rewrite rules. This fix restricts the rewrite rule to the
  single sign-on directory.
* Raw service provider configurations can now be added to udm 
  saml/serviceprovider objects. The configuration will be replicated
  to all domain IdP servers. In addition, the configuration option of
  simplesamlphp LDAP get_attributes is now done in LDAP. The current 
  value set to the UCR variable is migrated to the updated configuration