monitoring: Fix view monitoring health when Icinga is not running

If Icinga is not running, the view Monitoring Health simply shows a message about the backend not being up and running.
This is of course not so useful as it lacks performance and last runtime information but is does not error.

modules/monitoring/application/controllers/ProcessController.php

@@ -66,6 +66,9 @@ class Monitoring_ProcessController extends Controller
             )
             ->getQuery()
             ->fetchRow();
+        if ($programStatus === false) {
+            return $this->render('not-running', true, null);
+        }
         $this->view->programStatus = $programStatus;
         $toggleFeaturesForm = new ToggleInstanceFeaturesCommandForm();
         $toggleFeaturesForm

modules/monitoring/application/views/scripts/process/not-running.phtml

@@ -0,0 +1,6 @@
+<div class="controls">
+    <?= $this->tabs ?>
+</div>
+<div class="content">
+    <?= sprintf($this->translate('%s is currently not up and running'), $this->backendName) ?>
+</div>