EDD Edit Required Fields

gistfile1.php

<?php // DON'T COPY THIS LINE

/*
 * Remove Billing State from required list
 */
function custom_edd_purchase_form_required_fields( $required_fields ) {
    unset( $required_fields['card_state'] );
    return $required_fields;
}
add_filter( 'edd_purchase_form_required_fields', 'custom_edd_purchase_form_required_fields' );