SPRINGFIELD — Gov. Bruce Rauner was one of four Republican governors whose signature was missing from the letter supporting Brett Kavanaugh’s Supreme Court nomination Wednesday. But by the end of the day, Rauner’s name was added.Kavanaugh was tapped to become the next Supreme Court justice by President Donald Trump on July 9. The following day, Rauner applauded Trump’s choice and urged his confirmation. But a version of the letter backing Senate confirmation was missing Rauner’s signature …