Bug: deriving private key will fail if index is larger than that of decryptedShares.length

[metalurgical]

Maximum index of decrypted shares should be used here instead of decryptedShares.length in order to get the correct kCombinations in all instances:

torus.js/src/helpers/nodeUtils.ts

Line 503 in 0160ae8

const allCombis = kCombinations(decryptedShares.length, minThreshold);

This is reproducible in the following scenario:

threshold = 3
decryptedShares.count = 3
indexes: [2,3,4]

kCombinations will not include a combination for [2,3,4]