FRANKFURT (Reuters) -Germany’s Rehden gas storage facility, the biggest in western Europe, is being filled from May 5 to help Europe’s top economy build up supplies and soften the blow from potential Russian supply stops, the trustee of Gazprom Germania, its owner, said. “From today, small volumes are being injected,” Egbert Laege, the trustee who was appointed last month by the German energy regulator to manage the company temporarily, told Reuters in his first interview. “We are working intensively on solutions to ensure that already soon significantly more gas can flow into the storage faci…