Microsoft is shutting down its main LinkedIn service in China later this year as Beijing tightens its internet rules. The company said in a blog post Thursday it has faced a "significantly more challenging operating environment and greater compliance requirements in China." Microsoft is the latest American tech giant to lessen its ties to the country after years of trying to tailor its services to the demands of government censors. LinkedIn said it will replace its localized platform in China with a new app called InJobs that has some of LinkedIn's career-networking features but will not include a social feed…