Fix exception for new error stuff in Conduit

Summary: This might be `null`.

Test Plan: Loaded, got exception, applied patch, no exception. Viewed a method with an actual message too, that also worked.

Reviewers: chad, btrahan

Reviewed By: chad

CC: aran

Differential Revision: https://secure.phabricator.com/D7955

src/applications/conduit/controller/PhabricatorConduitConsoleController.php

@@ -112,9 +112,12 @@ final class PhabricatorConduitConsoleController
 
     $form_box = id(new PHUIObjectBoxView())
       ->setHeaderText($method->getAPIMethodName())
-      ->setErrorView($status_view)
       ->setForm($form);
 
+    if ($status_view) {
+      $form_box->setErrorView($status_view);
+    }
+
     $crumbs = $this->buildApplicationCrumbs();
     $crumbs->addTextCrumb($method->getAPIMethodName());