© Reuters. FILE PHOTO: Advertisements for crypto exchange show a Bitcoin symbol at Mass Transit Railway (MTR) station, in Hong Kong, China. October 27, 2021. REUTERS/Tyrone Siu (Corrects spelling of company name to Metalpha in last paragraph) By Georgina Lee HONG KONG (Reuters) -Hong Kong's government has proposed allowing retail investors to trade in cryptocurrencies and crypto exchange-traded funds – a move it hopes will help it rebuild its fintech hub status. The city, which previously proposed limiting crypto trade to professional investors, has seen planned rules for digital assets heavily criticised for stifling innovation, prompting a slew of start-ups…