(Reuters) – British sprinter Richard Kilty said he missed out on sending his son to school with an Olympic medal because team mate Chijindu Ujah failed to adhere to rules that would have prevented his positive dope test and their Tokyo silvers being stripped. Britain were stripped of the men’s 4x100m relay silver medal after the Court of Arbitration for Sport (CAS) upheld Ujah’s anti-doping rule violation on Friday. Ujah and his team mates Kilty, Zharnel Hughes and Nethaneel Mitchell-Blake finished second behind Italy but Canada will now be upgraded to silver while China get the bronze. Ujah d…