Volunteer lifeguards from Spanish charity Open Arms assisted 54 migrants stranded on a rubber dinghy in the Mediterranean Sea off the Italian island of Lampedusa on Tuesday, according to a Reuters witness.The group said it gave the passengers, who were mainly Syrian nationals, life jackets and water after alerting the Italian Coast Guard, which later took them to Lampedusa.The central Mediterranean is one of the most dangerous routes for refugees seeking asylum in Europe. Last year…