Reinstated 1 mirror.

Beer's mirror is undergoing maintenance, and should be good real soon now.

source/get-devuan.html

@@ -133,11 +133,9 @@
               <li>
                 <a href="https://mirror.operationtulip.com/devuan/"><span class="icon-download"></span> mirror.operationtulip.com/devuan/</a>
               </li>
-<!-- Currently down ...
               <li>
                 <a href="https://devuan.rosset.eu.org/devuan-files/"><span class="icon-download"></span> devuan.rosset.eu.org/devuan-files/</a>
               </li>
--->
 <!-- Requests username and password ...
               <li>
                 <a href="https://mirrors.ocf.berkeley.edu/devuan-cd/"><span class="icon-download"></span> mirrors.ocf.berkeley.edu/devuan-cd/</a>