Fixed 64-byte hashes
Created by: max619
Currently hashes with 64-byte long output are calculating incorrectly because of incorrect if statement
You can see implementation of blake2b_long
method in reference repository.
That PR will fix this problem.
Also, it would be nice to add test for keys longer then 32 bytes (at least for this corner case), however it will lead to rewriting some part of test code, and i'm not really sure if it needed