There was a time when Gossip performed at Berlin’s techno stronghold Berghain. That was before the US punk indie band it entered a period of mainstream success that saw them shoot to worldwide fame thanks to hits like “Heavy Cross.” Now, singer Beth Ditto, guitarist Nathan Howdeshell and drummer Hannah Blilie are back in Berlin to promote their new album, more than a decade after they last released a record and some 7 years after they broke up in 2016. “Real Power” is Gossip’s sixth album and set for release on March 22, and the newly reunited trio have embarked on a heavy promo marathon, incl…