ED Koch hasn’t changed his mind about Rudy Giuliani since he wrote “Giuliani: Nasty Man” in 2000. “In my opinion, it would be very harmful to our country if Rudy were to become president. Rudy simply does not tell the truth when it suits him not to,” Koch says in a mass e-mail. He’s writing a new intro to his book, to be reissued by Barricade. Koch cited four instances where he says Giuliani lied, and, “There will be much more on Rudy’s record as he is examined by the national media.”