Don't recommend installing without a reverse proxy

(It was a placeholder anyway)

source/installation/proxy.html.md

@@ -12,7 +12,6 @@ your reverse proxy in this list:
   <li><a href="/installation/proxy/nginx">Nginx</a></li>
   <li><a href="/installation/proxy/apache">Apache</a></li>
   <li><a href="/installation/proxy/iis">IIS</a></li>
-  <li><a href="/installation/proxy/none">No reverse-proxy</a></li>
 </ul>
 
 If you don't have a reverse-proxy on your server yet but want one, we recommend

source/installation/proxy/none.html.md

@@ -1,5 +0,0 @@
----
-title: Running Plume without a reverse-proxy
----
-
-This part is not documented yet.