The late-night host called this guest his “white whale.” You could say that Stephen Colbert is thirsty … for the purveyor of some very fine wine. The host of “The Late Show” told the Hollywood Reporter in an interview published Wednesday that there is still one dream guest he’s “desperate” to get on his show before its final episode on Thursday, May 21. “The pope is my white whale,” Colbert, a devout Catholic, said of Pope Leo XIV . “I wrote him. I said, ‘Come on!’ No, I said, ‘Your Holiness, I