After surviving a scare in Game 1 of the Eastern Conference finals, Joe Mazzulla isn’t ruling out lineup tweaks for Game 2. The Celtics coach said he would be open to using Jayson Tatum as a center in small-ball lineups after Boston struggled at times to match Indiana’s pace in Tuesday’s 133-128 overtime win at TD Garden. “You’ve got to be ready to just go to anything and everything,” Mazzulla said after Wednesday’s practice. Outside of bench-em…