(200, 200, 2) array makes 3d convolution segfault

[svenpeter42]

just needs some sanity checking. test case adapted from #13

import fastfilters
import numpy as np

data = np.random.normal(size=(200, 200, 2))
data = fastfilters.hessianOfGaussianEigenvalues(data, window_size=3.5, scale=3.5)