httpinstance: retry request without ipa-ca.$DOMAIN dnsName on failure
In the migration case of replica installation, if the CA server is
an older version it may not support the ipa-ca.$DOMAIN dnsName in
the HTTP cert (it is a special case in the cert_request command).
Therefore if the request fails, try it again without the
ipa-ca.$DOMAIN dnsName.
Part of: https://pagure.io/freeipa/issue/8186
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>