What a whirlwind holiday for Jack Ma and his fintech empire. The People’s Bank of China, the country’s central bank, summoned Ant Group for regulatory talks on December 26th, announcing a sweeping plan for the fintech firm to “rectify” its regulatory violations. The meeting came less than two months after China’s financial authorities abruptly halted what could have been a record-setting initial public offering of Ant over the firm’s regulatory compliance issues. The company, which started out as a payments processor for Alibaba’s online marketplaces and spun out in 2011,…