were stored in cache by pointers, which caused falsy cache hits in loop
because pointers with same address were created for different block
numbers. Now cache uses block numbers of uint64 as key, which can
overflow but it is not a problem since we use this cache for values
comparison, not as user data.
Fix crash on nil pointer in log.
Remove some unused code.
Protect nonceRanges with mutex while reading.
Updates #10246
IvanBelyakoff