BEIJING – President Trump can’t use his beloved cellphone while in China, one of the many logistical challenges that he and White House staff faced on the ground in Beijing . The president, like all travelers to China, was told not to use personal devices in order to protect his data from hackers. It makes for a tough few days for Trump , who is a frequent phone user — dialing friends, taking calls from reporters, and posting memes. A White House official confirmed the president wouldn’t be