fix rounding problem in timespan unit test
fix rounding problem in timespan unit test

maekitalo/cxxtools,OlafRadicke/cxxtools,maekitalo/cxxtools,OlafRadicke/cxxtools,maekitalo/cxxtools,maekitalo/cxxtools,OlafRadicke/cxxtools,OlafRadicke/cxxtools