Resolve #3485274 "Task delete functionality"

Closes #3485274

src/Form/DeleteTaskForm.php

@@ -42,8 +42,8 @@ class DeleteTaskForm extends ConfirmFormBase {
     $content_id = $this->id;
     $response = \Drupal::service('todoist_api.client')->delete($uri, $content_id);
     if($response):
-      $form_state['redirect'] = '/admin/content/todois';
-      //return new Url('todoist_api.taskscontroller');
+      $this->messenger()->addStatus($this->t('A task has been deleted.'));
+      $form_state->setRedirect('todoist_api.taskscontroller');
     endif;
   }