Improvement: Restart a FPM process when it is not running
As in !737 (merged) mentioned, a PHP FPM master may not start, when it has not at least one pool file. This may lead to not restart the master, even if ISPConfig may have created a new pool file. This is due to the "problem", that in systemd environments ISPConfig tries to reload the FPM master, but doesn't do a restart on problems.