SPRINGFIELD — An expansion of a state law that aims to curtail gender-based pay differences could soon be headed to the governor’s desk. House Bill 2462 would prohibit employers from asking about or screening potential workers based on their pay history. Exceptions would be if the salary was public knowledge or if an employee was employed at the company and the company had an established pay schedule. The bill would also allow a prospective employee to avoid revealing his or her salary history. The legislation, now …