March 1 (Reuters) - Ukrainian President Volodymyr Zelenskiy said on Sunday that the changes in Iran brought about by U.S. and Israeli strikes should be "used properly" to benefit the country's people who had withstood violence from their authorities. Zelenskiy, speaking in his nightly video address, said Iran's authorities had killed "tens of thousands of people in the last couple of months alone," referring to a crackdown on protests. Iran, he said, had "predetermined the way it is treated" by supplying attack drones to Russia in Moscow's four-year-old conflict in Ukraine and had also "fomented wars in the region." "It...