The default is openssl.cnf The project seems to prefer xxx.conf these
days, but we should use the default convention.
Rename all foo.conf (except for Configurations) to foo.cnf
Fixes#11174
Reviewed-by: Paul Yang <kaishen.yy@antfin.com>
Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
(Merged from https://github.com/openssl/openssl/pull/11176)
