compare broken where the first array cells are zeros

[gdementen]

The "maximum absolute relative difference" is displayed as 0 instead of 'inf' and all cells are colored white, which makes it very misleading.

On the other hand "differences only" sees those differences just fine.

arr1 = ndtest((2, 3))
arr2 = arr1.copy()
arr2['a0', 'b0'] = 42
compare(arr1, arr2)

In the session comparator, the array is colored red as it should though:

s1 = Session(arr1=arr1)
s2 = Session(arr1=arr2)
compare(s1, s2)

[gdementen]