A man wearing a mask walks by the Shanghai Stock Exchange building at the Pudong financial district in Shanghai, China, February 3, 2020. REUTERS/Aly Song/File Photo Acquire Licensing Rights Sept 4 (Reuters) – China is launching a campaign to revive its lagging stock market, and boost investor confidence in an ailing economy. A slew of measures announced include reducing trading costs, slowing the pace of initial public offerings (IPOs), encouraging margin financing and protecting small investors. The securities regulator also introduced fresh measures on Friday to improve the two-year old Beijing Stock Exchange, focusing on boosting the market's liquidity. Here…