Apr. 21—OKLAHOMA CITY — The NBA’s best road team in the regular season stepped into a hostile environment Sunday. Every seat at Paycom Center was occupied 20 minutes before tipoff. The 18,203 in attendance wore white. Oklahoma City Mayor David Holt whipped the crowd into a frenzy from midcourt before the game was tipped. The New Orleans Pelicans remained composed for most of Game 1. But with…