cryptcheck: make reading of nonce more efficient with RangeOption #1825
cryptcheck: make reading of nonce more efficient with RangeOption #1825

...also only calculate the required hash which will speed things up slightly.

B4dM4n/rclone,yonjah/rclone,B4dM4n/rclone,ncw/rclone,yonjah/rclone,B4dM4n/rclone,ncw/rclone,seuffert/rclone,seuffert/rclone,olihey/rclone,B4dM4n/rclone,yonjah/rclone,ncw/rclone,olihey/rclone,yonjah/rclone,ncw/rclone,olihey/rclone,seuffert/rclone,olihey/rclone,seuffert/rclone