By Kirstin Ridley and Elizabeth Howcroft LONDON, Feb 10 - Britain's Financial Conduct Authority said on Tuesday it had asked social media companies and app stores to block access to crypto exchange HTX in ​the UK, stepping up efforts to prevent the group from promoting "illegal" crypto asset services. The regulator, which filed a London ‌High Court lawsuit against HTX last October, said it wanted Alphabet's Google and Apple to remove HTX products from UK app stores and HTX's ‌social media accounts for ...