Additional PHP FPM server
By default Virtualmin will attempt to find the PHP FPM server by searching
system packages, but if you have manually installed it in a different location
by compiling from source, the path to the FPM server can be set here. This is
also useful on other operating systems like FreeBSD where Virtualmin doesn't
know how PHP-FPM is packaged. If this option is set, you should also set the
two following options.