Use unsigned byte for weight

wii-pair/daemon.py

@@ -200,13 +200,13 @@ try:
                     v = 0
                     if w.weight is not None:
                         v = round(w.weight)
-                    r += struct.pack('b', v)
+                    r += struct.pack('B', v)
                 elif m[0] == ord('b'):
                     # Return battery
                     v = 0
                     if w.board.battery is not None:
                         v = round(w.board.battery*100)
-                    r += struct.pack('b', v)
+                    r += struct.pack('B', v)
                 else:
                     # Return balance
                     if w.pos_x is None: