Quiero instalar usando un proxy inverso para Apache

Gracias.
Seguí la guía para construir Discourse.
Sin embargo, el proxy inverso en Apache no funciona correctamente.

    ProxyPass /  ws://var/discourse/shared/standalone/nginx.http.sock
    ProxyPassReverse / ws://var/discourse/shared/standalone/nginx.http.sock

Error

 No protocol handler was valid for the URL /favicon.ico (scheme 'ws'). If you are using a DSO version of mod_proxy, make sure the proxy submodules are included in the configuration using LoadModule.,