Add better prototype pic

doc/paper/rotohsm_paper.tex

@@ -95,9 +95,8 @@ This work contains the following contributions:
 \end{enumerate}
 
 \begin{figure}
-    % FIXME replace picture with publication-quality one
     \center
-    \includegraphics[width=8cm]{prototype_early_comms_small.jpg}
+    \includegraphics[width=8cm]{prototype_pic.jpg}
     \caption{The protoype when we first achieved reliable power transfer and bidirectional communication between stator
     and rotor. In the picture, the prototype was communicating reliably up to the maximum $\approx\SI{1500}{rpm}$ that
     we could get out of its hobby quadcopter parts.}