#3206933 Fix notice after installation

Closes #3206933

src/Form/SettingsForm.php

@@ -103,7 +103,7 @@ class SettingsForm extends ConfigFormBase {
         $form['enabled_entity_types'][$entity_type_id][$bundle_id] = [
           '#type' => 'checkbox',
           '#title' => $bundle['label'],
-          '#default_value' => $enabled_entity_types[$entity_type_id][$bundle_id],
+          '#default_value' => !empty($enabled_entity_types[$entity_type_id][$bundle_id]) ? $enabled_entity_types[$entity_type_id][$bundle_id] : false,
         ];
       }
     }