Years of aggressive expansion and flawed corporate governance have laid bare fresh vulnerabilities in China’s banking system, prompting regulators to step in to rescue an underperforming regional player.Zhongbang Bank, a lender in central China’s Hubei province mired in a credit crisis, has become the latest to force Beijing into action amid official clean-up efforts to create a healthy banking system.The National Financial Regulatory Administration (NFRA) announced on Friday that it would...