LONDON (Reuters) - British insurer RSA posted an above-forecast operating profit of 656 million pounds in 2019, helped by strong underwriting performance and a restructuring of its international commercial business, it said on Thursday.Operating profit excluding exits was forecast at 644 million pounds, according to a company-supplied consensus poll.Home, motor and commercial insurer RSA, best known in Britain for its "More Than" brand, also has major businesses in Canada, Ireland and..