Some versions of openssl might have the CMS feature disabled
LibreSSL disables this feature too
If the feature is disabled, fallback to PKCS7

In file included from scripts/sign-file.c:46:0:
/usr/x86_64-pc-linux-gnu/include/openssl/cms.h:62:2: error: #error CMS is disabled.
 #error CMS is disabled.
Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
Signed-off-by: David Howells <dhowells@redhat.com>