Kim Kardashian — along with her mother Kris and sisters Khloé & Kylie — are demanding the court block Blac Chyna from talking about their brother Rob dropping a lawsuit against his ex-days before trial. According to court documents obtained by Radar, the Kardashian/Jenner family is now asking for any testimony about Rob’s decision to be banned from the upcoming trial with Chyna. Chyna is suing the family accusing them of causing her reality show Rob & Chyna to be canceled. She believes they spread lies to E! execs that she abused Rob. In court, she claims Kris came up with the lie and told Kim…