PR 320 introduced a bug that causes the `blocks` and `lengths` database
files to be located one directory level higher than it they should be.
The bug doesn't cause any functional problem, it only makes the
lightwalletd do more work (re-download the block cache), and it also
makes it not possible to switch between testnet and mainnet.
This patch locates the database files back where they belong.
adityapk00
Larry Ruane