Improvement for web_module.inc.php as it may (re)start a non-running PHP FPM master.

The background of this MR is, that you may rollout multiple PHP versions to a server but not all should be started automatically. As long as not at least one valid conf is given, the process won't start. So you have the posibility to give your customers more PHP versions to select w/o having each PHP FPM master started, what may be a big memory consumption w/o any kind of advantage. Or better said, it may be a disadvantage on smaller VMs with just 1-2 GB RAM when there are already running 4-6 FPM masters which may consume up to 200MB w/o doing anything.