Also remove the initial block load (all blocks will come from the
Staging APIs), but there is still more to do (this does not even
start up correctly) but darkside.proto is correct, we believe.
Follow-on to previous commit. Without this change,
darksidewalletd detects corruption, example:
{..."CORRUPTION detected in db blocks-cache files, height 1000..."}
Steps to recreate default-darkside-blocks:
$ mkdir blocks
$ touch blocks/{1000,1001,1002,1003,1004,1005}.txt
$ go run cmd/genblocks/main.go >testdata/default-darkside-blocks