ISN'T Madonna supposed to be controversial and independent? Then why did she cancel all three Israel stops on her "Reinvention Tour"? At least now we know how she's reinventing herself: as someone who plays it safe. The whole tour, in fact, plays it safe. It takes nothing to spout antiwar messages and to bash Republicans, President Bush and the U.S. military. Nor is there any longer anything provocative about getting naked and simulating heterosexual and lesbian sex.