message: Guard non-free usage in stitching as contrib can be built without it.
diff: namespace opencv_test { namespace {
  -#ifdef HAVE_OPENCV_XFEATURES2D
  +#if defined(HAVE_OPENCV_XFEATURES2D) && defined(OPENCV_ENABLE_NONFREE)
  TEST(SurfFeaturesFinder, CanFindInROIs)
  {
  @@ -74,7 +74,7 @@ TEST(SurfFeaturesFinder, CanFindInROIs)
  ASSERT_EQ(bad_count, 0);
  }
  -#endif // HAVE_OPENCV_XFEATURES2D
  +#endif // HAVE_OPENCV_XFEATURES2D && OPENCV_ENABLE_NONFREE
  TEST(ParallelFeaturesFinder, IsSameWithSerial)
  {
  