Fix a minor issue with killing daemons

Summary: Even if you --force, we can't kill PID 0. This sends the process itself the signal, and terminates it.

Test Plan: See D11786.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D11787

src/applications/daemon/management/PhabricatorDaemonManagementWorkflow.php

@@ -508,7 +508,9 @@ abstract class PhabricatorDaemonManagementWorkflow
       $pid = $daemon->getPID();
       $name = $daemon->getName();
 
-      if (!$pid && !$force) {
+      if (!$pid) {
+        // NOTE: We must have a PID to signal a daemon, since sending a signal
+        // to PID 0 kills this process.
         $console->writeOut("%s\n", pht("Daemon '%s' has no PID!", $name));
         unset($daemons[$key]);
         continue;