Google cache: http://webcache.googleusercontent.com/search?q=cache:8jVuBmx...
Now I turned the PHP page into a static HTML one and it's back online.
Configuring web servers is a minefield :)
Edit: But you are not alone. Elsewhere in the thread: https://news.ycombinator.com/item?id=12797032
Google cache: http://webcache.googleusercontent.com/search?q=cache:8jVuBmx...