WPP is fighting back against a lawsuit filed by one of its former executives.WPPWPP alleges in a legal filing that a former exec improperly leaked sensitive information in his lawsuit against the company.WPP is asking the court to seal several paragraphs, figures, and exhibits from the lawsuit.A lawyer for the former exec said he will "oppose any attempt to seal the facts of this case."Ad giant WPP is fighting back against a lawsuit filed by one…