Remove DAYS argument

Remove DAYS argument

This commit removes DAYS from certificate requests to avoid the warning

'Ignoring -days without -x509; not generating a certificate'

This argument is not needed with the -new argument. Additionally makes sure
$1 is handled when -nodes is not given. Preventing an uninitialized value
error when the DAYS argument is removed.

Fixes #26595

CLA: trivial

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Tom Cosgrove <tom.cosgrove@arm.com>
(Merged from https://github.com/openssl/openssl/pull/27277)

(cherry picked from commit d890ad2b96efea4f5f4b0db190017ce9a3897df7)