Even though Universal’s original ABBA sequel Mamma Mia! Here We Go Again was unexpectedly beat by Sony’s Equalizer 2 for the No. 1 spot at the weekend B.O., $35.8M to $34.4M, the Universal City lot can celebrate that they’ve clicked past the $1 billion mark at the domestic box office, making it their eighth time in a row to do so. Overall this weekend, four Universal titles took four spots in the box office’s top 10 including Mamma Mia 2, Jurassic World: Fallen…