Merge pull request #45078 from Izorkin/syslog-ng-reload-fix

syslog-ng: fix reload service

nixos/modules/services/logging/syslog-ng.nix

···
       after = [ "multi-user.target" ]; # makes sure hostname etc is set
       serviceConfig = {
         Type = "notify";
+        PIDFile = pidFile;
         StandardOutput = "null";
         Restart = "on-failure";
         ExecStart = "${cfg.package}/sbin/syslog-ng ${concatStringsSep " " syslogngOptions}";
-        ExecReload = "${pkgs.coreutils}/bin/kill -HUP ${pidFile}";
+        ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";
       };
     };
   };