only in patch2:
unchanged:
--- a/core/modules/field/src/Plugin/migrate/process/d7/FieldSettings.php
+++ b/core/modules/field/src/Plugin/migrate/process/d7/FieldSettings.php
@@ -24,10 +24,19 @@ class FieldSettings extends ProcessPluginBase {
   public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
     $value = $row->getSourceProperty('settings');
 
-    if ($row->getSourceProperty('type') == 'image' && !is_array($value['default_image'])) {
-      $value['default_image'] = array(
-        'uuid' => '',
-      );
+    switch ($row->getSourceProperty('type')) {
+      case 'image':
+        if (!is_array($value['default_image'])) {
+          $value['default_image'] = array('uuid' => '');
+        }
+        break;
+
+      case 'taxonomy_term_reference':
+        $value['target_type'] = 'taxonomy_term';
+        break;
+
+      default:
+        break;
     }
 
     return $value;