Some systems such as FreeBSD identify the platform as 'arm64' and not 'aarch64' as Linux does. Signed-off-by: Rebecca Cran <rebecca@bluestop.org> Reviewed-by: Liming Gao <liming.gao@intel.com> Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> [lersek@redhat.com: fix up DKIM damage in the "From:" address]