BEIJING, May 24 (Reuters) – The death toll has risen to three with 17 missing following flooding in the Chongqing municipality of southwestern China, China’s state-run Xinhua reported. That was as of 2:30 pm (0630 GMT) on Sunday, after Chongqing’s Yongchuan district was hit with sudden extreme rainfall from Saturday night through the early hours of Sunday, Xinhua said. Rescue work is underway. China’s state planner allocated 20 milli…