BOSTON—Stephen Curry was still aglow over becoming the NBA’s all-time 3-point shooter when the Warriors got a scare that’s becoming frighteningly common in the league—and other sports, too: Guard Jordan Poole was placed into COVID-19 protocols. “We’re coming off the emotional roller coaster … a lot going on around the league,” Curry said after scoring 30 points in a 111–107 victory over the Celtics on Friday night. “You try not to get distracted by all the things that are outside the locker room.” One game after breaking Ray Allen’s 3-point record at Madison Square Garden, Curry hit five 3-pointers and added a one-handed scoop shot in the final minute to help the Warriors snap a five-game losing streak against the Celtics. Andrew Wiggins scored 27 and Kevon Looney had 10 rebounds for the Warriors, who won their third straight game on an East Coast road trip to reclaim sole possession …