ipatests: mark known failures as xfail
The tests in test_integration/test_installation.py
that inherit from InstallTestBase2 all fail in
test_replica2_ipa_kra_install because of ticket
7654: ipa-kra-install fails on DL1
This is an issue linked to dogtag (see
https://pagure.io/dogtagpki/issue/3055), where the
installation of a KRA clone creates a range depletion
when multiple clones are created from the same master.
Marking the tests as known failure, waiting for dogtag's
fix.
Related to https://pagure.io/freeipa/issue/7654
Reviewed-By: Christian Heimes <cheimes@redhat.com>