Update apache_configuration.markdown (home-assistant#1777)

elbowz · fabaff · commit b73af61eb93c · 2017-02-13T12:54:47.000+01:00
diff --git a/source/_cookbook/apache_configuration.markdown b/source/_cookbook/apache_configuration.markdown
@@ -23,6 +23,9 @@ This is useful if you want to have:
 So you already have a working Apache server available at example.org.
 Your home assistant is correctly working on this web server and available at localhost:8123
 
+Enable `mod_proxy_wstunnel` by running:
+`sudo a2enmod proxy_wstunnel`
+
 To be able to access to your home assistant instance by using https://home.example.org, add to following file into `/etc/httpd/conf/extra/hass.conf`
 
 ```text
