Fix description text, streamline some code

simple_sitemap.module

@@ -221,7 +221,7 @@ function simple_sitemap_delete_bundle_config($entity_type_id, $bundle) {
 
     $message = "You may want to <a href='@url'>regenerate</a> your XML sitemap now.";
     if ($generator->getSetting('cron_generate')) {
-      $message .= ' Otherwise the sitemap will be regenerated on the next cron run.';
+      $message .= ' Otherwise the sitemap will be regenerated during a future cron run.';
     }
     drupal_set_message(t($message, ['@url' => $GLOBALS['base_url'] . '/admin/config/search/simplesitemap']));
   }

src/Batch/UrlGeneratorBase.php

@@ -173,7 +173,7 @@ class UrlGeneratorBase {
       : $this->languages;
 
     // Entity is not translated.
-    if (NULL !== $entity && isset($translation_languages['und'])) {
+    if ($entity instanceof ContentEntityBase && isset($translation_languages['und'])) {
       if ($url_object->access($this->anonUser)) {
         $url_object->setOption('language', $this->languages[$this->defaultLanguageId]);
         $alternate_urls[$this->defaultLanguageId] = $this->replaceBaseUrlWithCustom($url_object->toString());

src/Form/FormHelper.php

@@ -203,7 +203,7 @@ class FormHelper {
       '#default_value' => FALSE,
     ];
     if ($this->generator->getSetting('cron_generate')) {
-      $form_fragment['simple_sitemap_regenerate_now']['#description'] .= '</br>' . $this->t('Otherwise the sitemap will be regenerated on the next cron run.');
+      $form_fragment['simple_sitemap_regenerate_now']['#description'] .= '</br>' . $this->t('Otherwise the sitemap will be regenerated during a future cron run.');
     }
   }