Cologne police on Wednesday said an incident at a western German military airbase is now being treated as a trespassing case, after initial suspicions of sabotage to the base’s water supply proved unfounded. A spokeswoman said police are investigating after an “unauthorized person” was spotted on the Cologne-Wahn airbase early on Wednesday, leading military officials to conduct an unsuccessful search. Earlier reports suggested the unidentified individual may have tampered with the barracks’ water supply. A spokesman for the German Air Force earlier said abnormal water levels had been recorded,…