By Andrew Osborn LONDON (Reuters) - Foreign Secretary William Hague called on Britain and Germany to lead a campaign to reform the European Union on Friday as he explained how the bloc could be overhauled and derided planned EU financial services regulation as "folly". In a speech in Germany aimed at persuading Europe's most powerful nation to back Prime Minister David Cameron's plans to try to reform the EU ahead of a possible British EU membership referendum, Hague set out some of the changes Cameron hopes to win. "We want to get on with the business of delivering that reformed EU. ...