don't throw exception if we detect no threaded MPI, we support it now
don't throw exception if we detect no threaded MPI, we support it now

MengjiaoH/ospray,ospray/OSPRay,ospray/OSPRay,MengjiaoH/ospray,wilsonCernWq/ospray,wilsonCernWq/ospray,MengjiaoH/ospray,ospray/OSPRay,ospray/OSPRay,MengjiaoH/ospray,wilsonCernWq/ospray,MengjiaoH/ospray