Custom callback for AJAX Chosen (select field) doesn't get the term as argument. #173

AJAX hook callback doesn't supply the term as argument for custom callback due to wrong if statement in the default case of AJAX callback.

https://github.com/Codestar/codestar-framework/blob/54e23323b8f7deff8d18f5697144b04585d2267b/classes/fields.class.php#L261-L267C12