Add additional class to closebrowser rescue

Previously, closebrowser would throw a Selenium::WebDriver::Error::WebDriverError when closebrowser was called on either a non-existent browser or a system that could not bring up a browser.  Unfortunately, this would not throw an error in the at_exit hook in RSpec and cause the whole test to pass!  This fix adds the error and hopefully now, tests will no longer lie when they fail miserably.
version bump to 5.14.44