message: Honor fixing principal point in camera calib tutorial.
diff: @@ -147,6 +147,7 @@ public:
  if(fixK2) flag |= fisheye::CALIB_FIX_K2;
  if(fixK3) flag |= fisheye::CALIB_FIX_K3;
  if(fixK4) flag |= fisheye::CALIB_FIX_K4;
  + if (calibFixPrincipalPoint) flag |= fisheye::CALIB_FIX_PRINCIPAL_POINT;
  }
  calibrationPattern = NOT_EXISTING;
  