VfB Stuttgart’s main fan group called on Friday for the resignation of the club’s entire board following a power struggle which threatens to overshadow the Bundesliga team’s success on the pitch. Stuttgart have defied all expectations to sit third in the German men’s top flight this term and look set to reach Europe’s lucrative Champions League next season. But a row involving Porsche, which has joined fellow Stuttgart carmaker Mercedes in heavily investing in the club, has been bubbling in the background. As there can be no “peaceful future” in the current situation, the fans believe that pre…