fixed "RuntimeError: structure and input must have equal rank"

[mese79]

In block_face_adjacency_graph function of distributed_segmentation the assumption for the face dimensions is 3D while it will raise an error if you pass 2D input (blocks).

File /miniforge3/envs/cellpose/lib/python3.10/site-packages/scipy/ndimage/_measurements.py:182, in label(input, structure, output)
    180 structure = np.asarray(structure, dtype=bool)
    181 if structure.ndim != input.ndim:
--> 182     raise RuntimeError('structure and input must have equal rank')

I update the code so the structure will have the same rank as the face (here):

structure = scipy.ndimage.generate_binary_structure(face.ndim, 1)

[carsen-stringer]

thanks, cc @GFleishman