images: Drop freeipa from debian-testing

It's too buggy right now, not even installable in unstable, and will
still take a long time until it re-enters debian testing.

Fixes #6377

images/scripts/debian.setup

@@ -119,17 +119,16 @@ if [ "$IMAGE" = "debian-testing" ]; then
     echo 'deb http://deb.debian.org/debian testing main' > /etc/apt/sources.list
     RELEASE=testing
 
+    # too buggy and uninstallable even in unstable, see https://tracker.debian.org/pkg/freeipa
+    IPA_CLIENT_PACKAGES="${IPA_CLIENT_PACKAGES/freeipa-client/}"
+
     # HACK: some packages fell out of testing, get them from unstable
     echo 'deb http://deb.debian.org/debian unstable main' >> /etc/apt/sources.list
     cat <<EOF > /etc/apt/preferences.d/unstable
 Package: *
 Pin: release a=unstable
 Pin-Priority: -1
 
-Package: *ipa*
-Pin: release a=unstable
-Pin-Priority: 10
-
 Package: *sss*
 Pin: release a=unstable
 Pin-Priority: 10