By Tom Wilson LONDON (Reuters) – Britain’s financial watchdog said on Monday it lacked the power to assess the “fitness and propriety” of new beneficial owners of digital asset custodian Digivault, after an arm of crypto exchange Binance launched a tie-up with Digivault’s parent. Crypto assets firm Eqonex, which owns Digivault, and the new payments arm of Binance, the world’s biggest crypto exchange, earlier said in a statement that the partnership would focus on “leveraging” Digivault, which is regulated by Britain’s Financial Conduct Authority. Under the deal, Bitfinity, the Binance unit, ha…