Cleaned up nested ifs in NPC.SpawnNPC().
Cleaned up nested ifs in NPC.SpawnNPC().

DeathCradle/Terraria-s-Dedicated-Server-Mod,DeathCradle/Terraria-s-Dedicated-Server-Mod,DeathCradle/Terraria-s-Dedicated-Server-Mod,DeathCradle/Terraria-s-Dedicated-Server-Mod