By Paul Sandle LONDON (Reuters) -London police chief Cressida Dick resigned on Thursday, Mayor of London Sadiq Khan said, after he told her he was not satisfied she could root out the racism, sexism and other problems that still existed within the force. Confidence in the Metropolitan Police has been shaken by the abduction, rape and murder of a woman, Sarah Everard, by one of its officers, and recent revelations of a culture of bullying, racial discrimination and misogyny in a central London police station. Khan said he had made clear to Dick the scale of the change he believed was urgently r…