compile fix - mpi now compiles (again) w/o distributed api extension
compile fix - mpi now compiles (again) w/o distributed api extension

MengjiaoH/ospray,ospray/OSPRay,wilsonCernWq/ospray,MengjiaoH/ospray,wilsonCernWq/ospray,Twinklebear/OSPRay,ospray/OSPRay,MengjiaoH/ospray,Twinklebear/OSPRay,MengjiaoH/ospray,Twinklebear/OSPRay,favreau/OSPRay,favreau/OSPRay,ospray/OSPRay,MengjiaoH/ospray,favreau/OSPRay,Twinklebear/OSPRay,ospray/OSPRay,wilsonCernWq/ospray,favreau/OSPRay