Reverse proxy subdomain to secondary application Nethserver

[carsten (Carsten Härle)]

I found a simpler solution. Just proxy to https instead of http (which is not working currently). This removes the need to change existing templates. However, the files webtop5-webdav.conf, webtop5-zpush.conf, webtop.conf still have to be removed, because the take precedence over the reverse proxy configuration.

Also I improved the reverse proxy to handle WebSockets automatically.

Improve reverse proxy, automatic handling of websockets

Many applications use websockets today (e.g. webtop5). The current reverse proxy module of Nethserver only adds ProxyPass and ProxyPassReverse, so Websockets are not passed correctly. The only solution is to not use the reverse proxy UI at all and create manual configurations in /etc/httpd/conf.d instead, which is however complicated and not shown in the UI. Fortunately it is possible to handle websocktets automatically by using the rewrite enginge: E.g. Reverse proxy xy.mydomain host to xy-ba…