Max inscribed ellipsoid segfault when given 2d polytope

[lucaperju]

Describe the bug
Sometimes, when trying to compute the max inscribed ellipsoid using the MAX_ELLIPSOID type, the process terminates with an instance of 'std::invalid_argument' thrown.

To Reproduce
Steps to reproduce the behavior:

1. Go to examples/sampling-hpolytope-with-billiard-walks/sampler.cpp
2. on line 78, change the EllipsoidType to MAX_ELLIPSOID
3. optionally, add a print before and after that line to confirm that the process is terminated while trying to compute the max ellipsoid
4. compile and run the example
5. See error

It could also be reproduced by trying to compute the max inscribed ellipsoid for various 2d polytopes until one which doesn't work is found, but above I described the fastest way to obtain this error.

Expected behavior
The function should be able to compute the max inscribed ellipsoid even if the polytope is two dimensional.

Screenshots