krainstance: set correct issuer DN in uid=ipakra entry
If IPA CA has custom subject DN (not "CN=Certificate
Authority,{subject_base}"), the uid=ipakra people entry gets an
incorrect 'description' attribute. The issuer DN in the
'description' attribute is based on the aforementioned pattern,
instead of the actual IPA CA subject DN.
Update KRAInstance.configure_instance() to require the CA subject DN
argument. Update ipaserver.install.kra.install() to pass the CA
subject DN.
Fixes: https://pagure.io/freeipa/issue/8084
Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>