Prying information loose about any Steven Spielberg project isn’t easy — just ask the Paramount execs who struggled to get a peek at “War of the Worlds” dailies. But that’s nothing compared to the shoot Spielberg began this month in Malta about Israel’s covert campaign to assassinate the Palestinian terrorists responsible for the massacre of Israeli athletes in the 1972 Munich Olympics. The Tony Kushner script is under such a lockdown that a Mossad agent would be hard-pressed to infiltrate its cover page. But Variety can at least reveal what that cover page starts with: “Munich.” That’s the official title of the film. Though not very descriptive, Spielberg’s inner circle can only hope the title might defuse the notion that the movie is based on “Vengeance,” a book based on input from a purported member of the hit team. Its veracity has been widely questioned.