API: tools: cibadmin --md5-sum-versioned no longer prints feature set

Previously, cibadmin --md5-sum-versioned printed the feature set version
to stderr in the form "Versioned (<version>) digest: ". This commit
drops that behavior.

The formatting was strange in the first place: it printed to stderr with
no trailing newline, relying on the digest printed to stdout to print a
newline.

Signed-off-by: Reid Wahl <nrwahl@protonmail.com>