The sign-file tool failed to build against libressl. Fix this by extending
the PKCS7 check and thus making sign-file link against libressl without an
error.
Signed-off-by: NJohn Crispin <john@phrozen.org>
Signed-off-by: NFelix Fietkau <nbd@nbd.name>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>