bpo-25910: Link redirections in docs (#1933)

Fixes some redirection links in docs.
diff --git a/Doc/using/unix.rst b/Doc/using/unix.rst
index 8b96ebe..ccdf84d 100644
--- a/Doc/using/unix.rst
+++ b/Doc/using/unix.rst
@@ -30,7 +30,7 @@
       for Debian users
    https://en.opensuse.org/Portal:Packaging
       for OpenSuse users
-   https://docs.fedoraproject.org/en-US/Fedora_Draft_Documentation/0.1/html/RPM_Guide/ch-creating-rpms.html
+   https://docs-old.fedoraproject.org/en-US/Fedora_Draft_Documentation/0.1/html/RPM_Guide/ch-creating-rpms.html
       for Fedora users
    http://www.slackbook.org/html/package-management-making-packages.html
       for Slackware users