Fix missing include in trace.h following 51df1f8841cae59faca9c8f8a39eb305a9a60b6f
Fix missing include in trace.h following 51df1f8841cae59faca9c8f8a39eb305a9a60b6f

egartner/MR-maze-exploration,egartner/MR-maze-exploration,egartner/MR-maze-exploration,egartner/MR-maze-exploration,egartner/MR-maze-exploration