By Joshua McElweeVATICAN CITY, March 5 (Reuters) - Pope Leo released a video on Thursday praying that God would help world leaders renounce war as a means of resolving conflicts in an unusual appeal as the U.S.-Israeli bombing campaign against Iran pressed on for the sixth day."Lord, enlighten the leaders of the nations, so they may have the courage to abandon projects of death," the pontiff said in the video message."Today we lift up our prayer for peace in the world, asking that nations renoun...