Changing arguments for the built-in taxonomies in WordPress

functions.php

<?php

function ofix_register_tax_args( $args, $taxonomy, $object_type ) {

    if ( 'link_category' === $taxonomy ) {
        $args['public'] = true;
        $args['query_var'] = true;
    }

    return $args;
}
add_filter( 'register_taxonomy_args', 'ofix_register_tax_args', 10, 3 );