Make find_certificate work when we don't need private keys.

Since we're calling find_certificate now from places that don't need
private keys, including one place that won't /have/ the private key,
that needs to be conditionalized.

Signed-off-by: Peter Jones <pjones@redhat.com>
Update version to 0.101

Signed-off-by: Peter Jones <pjones@redhat.com>