PHILADELPHIA, Sept 17 (Reuters) - U.S. Democratic presidential candidate Kamala Harris called on Tuesday for an end to the Israel-Gaza war and said that Israel must not reoccupy the Palestinian enclave once the nearly year-old conflict comes to an end. Speaking in Philadelphia to the National Association of Black Journalists, she called for a ceasefire between Israel and Palestinian Hamas militants, a two-state solution and Middle East stability in a way that does not empower Iran...