keep setting ipakrbprincipal objectclass on new service entries

this is required for replica promotion to work, since the ACI allowing hosts
to add their own services uses this objectclass as target filter.

This partially reverts changes from commit
705f66f749

https://fedorahosted.org/freeipa/ticket/5996

Reviewed-By: Petr Spacek <pspacek@redhat.com>
Reviewed-By: Martin Basti <mbasti@redhat.com>

ipatests/test_xmlrpc/objectclasses.py

@@ -100,6 +100,7 @@ service = [
     u'ipaobject',
     u'ipaservice',
     u'pkiuser',
+    u'ipakrbprincipal',
     u'top',
 ]
 

ipatests/test_xmlrpc/test_service_plugin.py

@@ -239,6 +239,7 @@ class test_service(Declarative):
                 result=dict(
                     dn=service1dn,
                     krbprincipalname=[service1],
+                    ipakrbprincipalalias=[service1],
                     krbcanonicalname=[service1],
                     objectclass=objectclasses.service,
                     ipauniqueid=[fuzzy_uuid],
@@ -301,7 +302,8 @@ class test_service(Declarative):
                     dict(
                         dn=service1dn,
                         krbprincipalname=[service1],
-                        krbcanonicalname=service1,
+                        ipakrbprincipalalias=[service1],
+                        krbcanonicalname=[service1],
                         objectclass=objectclasses.service,
                         ipauniqueid=[fuzzy_uuid],
                         has_keytab=False,