Jonathan Majors is back on a film set more than two years after pleading guilty to assaulting his ex-girlfriend Grace Jabbari ... though it's not exactly a mainstream Hollywood production. The actor who once worked in Marvel flicks is shooting a new untitled action movie in South Carolina for The Daily Wire ... the conservative media company founded by Ben Shapiro and film producer Jeremy Boreing. The other actors in the movie and the plot are being kept under wraps ... but the flick is supposed to be in the vein "Red Dawn" and "Toy Soldiers" -- two movies about...