add update hook for change in migration source

islandora.install

@@ -55,3 +55,15 @@ function islandora_update_8003(&$sandbox) {
     ->schema()
     ->dropTable('islandora_version_count');
 }
+
+function islandora_update_8004() {
+  $config_factory = \Drupal::configFactory();
+  $config = $config_factory->getEditable('migrate_plus.migration.islandora__tags');
+  if ($config) {
+    if (!$config->get('source.ids')) {
+      $config->set('source.ids', $config->get('source.keys');
+      $config->clear('source.keys');
+      $config->save(TRUE);
+    }
+  }
+}