vault-tool skips path when a secret has the same name at the same place

Hi,

I can confirm a bug in a particular situation where you have **a secret and a path that have the same name at the same location.**

Let's imagine these 2 secrets :
- secret/README
- secret/README/mysecret

When using vault-tool to dump or migrate data, it will not correctly handle the `secret/README/` path, and will just ignore it.

