Otherwise the ./config script fails with errors like:
> Operating system: x86_64-whatever-linux2
> This system (linux-x86_64) is not supported. See file INSTALL for details.
The failure was introduced by a93d3e0.
RT#4062
Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>