add comments to these two lines, like:
```
    # Port to listen to, example:
    # listen       80;
    listen       %PORT%;
    # Host and alias to respond to, example:
    # server_name  ez.no www.ez.no;
    # Alias can be skipped, and you can also provide several by using a whitespace to separate them, like:
    # server_name  ez.no www.ez.no www2.ez.no;
    server_name  %HOST% %HOST_ALIAS%;
```