处理在signup_nonce_fields()中创建的签名非授权。

function signup_nonce_check( $result ) {
	if ( ! strpos( $_SERVER['PHP_SELF'], 'wp-signup.php' ) ) {
		return $result;
	}

	if ( ! wp_verify_nonce( $_POST['_signup_form'], 'signup_form_' . $_POST['signup_form_id'] ) ) {
		$result['errors']->add( 'invalid_nonce', __( 'Unable to submit this form, please try again.' ) );
	}

	return $result;
}