Tyrese Maxey stood near center court, hands on his head and eyes wide open as the New Orleans Pelicans’ Nikeil Alexander-Walker stepped to the line for a pair of third-quarter free throws. The 76ers point guard’s pose exemplified his team’s Tuesday-night slog against an inferior opponent. It took until the fourth quarter for the Sixers to shake free to a 117-107 victory at the Wells Fargo Center. It was the Sixers’ 15th victory in 18 games since Christmas. But it was far from an inspired performance against a Pelicans team (18-29) that had won four of its past six games but was missing four st…