LONDON (Reuters) -The British government plans to introduce new legislation to overturn the wrongful convictions of hundreds of Post Office managers in one of the biggest miscarriages of justice in the country's history, Prime Minister Rishi Sunak said on Wednesday. Between 1999 and 2015, hundreds of self-employed sub-postmasters at branches of the state-owned Post Office - many of them at the heart of small communities and often run by family teams - were convicted of theft, fraud and false accounting because faulty computer software wrongly showed thousands of pounds missing from their...