vfs: change default --vfs-read-wait to 20ms
vfs: change default --vfs-read-wait to 20ms

In my testing with local and remote storage this is a good compromise
between delaying the seeks and failing to wait for in sequence reads.

See: https://forum.rclone.org/t/constantly-high-iowait-add-log/14156/40

ncw/rclone,ncw/rclone,ncw/rclone,ncw/rclone