The ladies of Real Housewives of Potomac better get their butts in gear if they plan on making it to Season 8’s reunion filming. RadarOnline.com has learned that Gizelle Bryant, Robyn Dixon, Candiace Dillard Bassett, Wendy Osefo, Mia Thornton, Karen Huger, and newcomer Nneka Ihim’s call time has been bumped to 4 AM — and if they aren’t on time, they’re SOL because Vice President Kamala Harris will be in the building. Rumor has it that Harris’ Wednesday guest appearance on Sherri Shepherd’s daytime show, Sherri, is throwing a major wrench into the RHOP reunion schedule and leaving producers scr…