Former President Donald Trump’s eldest son quietly deleted his debunked conspiracy theory about the upcoming debate Thursday after he was subjected to a brutal fact check. While House Republican Nancy Mace cried foul play over undisclosed “vitamins,” Trump Jr. decided to claim CNN would rig the debate by implementing a two-minute air-time delay. “Live TV has a seven second delay,” Trump Jr. wrote in the since-deleted tweet. “Why on earth would CNN need a 1-2 MINUTE delay unless they were planning on manipulating tonight’s debate?” Want more breaking political news? Click for the latest headlin…