message: Remove unused method availableControlCount()
diff: @@ -48,7 +48,6 @@ public:
  uint32_t robotControlMax() const { return mRobotControlMax; }
  uint32_t currentControlCount() const { return mRobotControlCount; }
  - uint32_t availableControlCount() const { return robotControlMax() - currentControlCount(); }
  const RobotList& robots() const { return mRobots; }
  