[Rpm-maint] Using https://ftp.rpm.org

[Jun Aruga]

https://github.com/rpm-software-management/rpm/releases/tag/rpm-4.14.0-release

> RPM releases are tracked at http://rpm.org/timeline
> Official RPM source releases are available at http://ftp.rpm.org/releases/, do not use GitHub provided tarballs.

Is it no problem and better to use https://ftp.rpm.org/releases/ rather than
http://ftp.rpm.org/releases/ ?

I got a error message on my Firefox browser. And seeing the web site
adding the exception to the browser.

```
The owner of ftp.rpm.org has configured their website improperly. To
protect your information from being stolen, Firefox has not connected
to this website.

ftp.rpm.org uses an invalid security certificate. The certificate is
only valid for the following names: osuosl.org, *.osuosl.org Error
code: SSL_ERROR_BAD_CERT_DOMAIN
```

I want the secure connection HTTPS from my program [1]. But
considering if it is okay because of the error message.

[1] https://github.com/junaruga/rpm-py-installer/issues/112

Jun