ipa-cert-fix: use customary exit statuses
It is customary to return 2 when IPA is not configured, and 1 when
other required bits are not installed or configured. Update
ipa-cert-fix exit statuses accordingly.
Part of: https://pagure.io/freeipa/issue/7885
Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>