boundingbox.py: Changed np.int to np.int32 to make compatible with ne…

…w versions of numpy (#624)

numpy.int is deprecated (>=1.20) or removed (>=1.24). This is
compatible back to >=1.13 and possibly earlier (earliest version for
which online documentation exists)

---------
Co-authored-by: Sameer Sheorey <sameer.sheorey@intel.com>

ml3d/vis/boundingbox.py

@@ -245,7 +245,7 @@ def plot_rect3d_on_img(img,
         if color is None:
             color = np.ones((line_indices.shape[0], line_indices.shape[1], 3))
         for i in range(num_rects):
-            corners = rect_corners[i].astype(np.int)
+            corners = rect_corners[i].astype(np.int32)
             # ignore boxes outside a certain threshold
             interesting_corners_scale = 3.0
             if min(corners[:, 0]