By Ju-min Park and Heekyong Yang SEOUL (Reuters) – In tears, Philomene Aby’s hands shook as she asked workers at a South Korean community centre for any news of her 22-year-old son, missing in the wake of a crowd surge in Seoul that left at least 151 people dead on Saturday. Her son, Masela, went to work at a club in the city’s Itaewon area around 6 p.m. on Saturday. That was the last time Aby, a Seoul resident from the Ivory Coast, saw him. “I called his number but … he wasn’t answering,” Aby told Reuters while standing in the Hannam-dong Community Service Center, which became a makeshift m…