fix issue 895 (scheduler creates zombies)

fix bug in windows : tasks did not start
cleanup

lib/classes/task/Scheduler.class.php

@@ -54,6 +54,11 @@ class task_Scheduler
      */
     public function run()
     {
+        if (function_exists('pcntl_signal')) {
+            // avoid <defunct> php when a task ends
+            pcntl_signal(SIGCHLD, SIG_IGN);
+        }
+
         $appbox = appbox::get_instance(\bootstrap::getCore());
         $registry = $appbox->get_registry();