monitoring: Select instance_name in multi-select views

Before, if all command transports are configured to filter for a specific instance, no command would have been sent to Icinga.

modules/monitoring/application/controllers/HostsController.php

@@ -49,7 +49,8 @@ class HostsController extends Controller
             'host_obsessing',
             'host_passive_checks_enabled',
             'host_problem',
-            'host_state'
+            'host_state',
+            'instance_name'
         ));
         $this->view->baseFilter = $this->hostList->getFilter();
         $this->getTabs()->add(

modules/monitoring/application/controllers/ServicesController.php

@@ -41,6 +41,7 @@ class ServicesController extends Controller
             'host_name',
             'host_problem',
             'host_state',
+            'instance_name',
             'service_acknowledged',
             'service_active_checks_enabled',
             'service_description',