BoundsError when struct contains 3D char array

MWE:

In Matlab create struct with 3D char array and save as .mat
```matlab
c1 = ['abc'; 'abc'];
char_array3D = cat(3, c1, c1)
s = struct('c', char_array3D)
save('s.mat', 's')
```

In Julia read .mat file containing 3D char array
```julia
using MAT
d = matread("s.mat")
```