force zero return for thread ID for non-external clients, since internal/driver clients have no separate thread
force zero return for thread ID for non-external clients, since internal/driver clients have no separate thread

ventosus/jack1,ventosus/jack1,drobilla/jack1,drobilla/jack1,ventosus/jack1,drobilla/jack1,drobilla/jack1,ventosus/jack1