Update u_e-80_to_443.md

docs/u_e-80_to_443.md

@@ -2,7 +2,7 @@ Since February the 28th 2017 mailcow does come with port 80 and 443 enabled.
 
 **Do not use the config below for reverse proxy setups**, please see our reverse proxy guide for this, which includes a redirect from HTTP to HTTPS.
 
-Open `mailcow.conf` and set `HTTP_BIND=0.0.0.0` - if not already set.
+Open `mailcow.conf` and set `HTTP_BIND=` - if not already set.
 
 Create a new file `data/conf/nginx/redirect.conf` and add the following server config to the file: