Approval.

en/actor_variant_types_set.php

@@ -4,3 +4,4 @@ $actor_variant_types_set['married_name'] = 'Married name';
 $actor_variant_types_set['monastic_name'] = 'Monastic name';
 $actor_variant_types_set['pseudonym'] = 'Pseudonym';
 $actor_variant_types_set['regnal_name'] = 'Regnal name';
+$actor_variant_types_set['nickname'] = 'Nickname';