Skip the parent assocation reference selector in the generate page function

The generate page will add reference selectors for assocations owned by the entity, which is handy in many cases. In case you generate for example the Orderline_NewEdit from the Order_NewEdit page it will contain a dropdown to select an Order. The order is defined by the main form and should not be changed in most cases. Please skip this referenceSelector in the form generator. Now they must be removed manually.