[gnocchi] Don't recursively modify file perms on start

For deployments with a lot of Gnocchi data, this is a non-starter
(literally... the service basically can't start.) There maybe needs to
be a way to configure this, or only do it during deploy/bootstrap?
Unclear, but disabling for now; users can `chown -R gnocchi:gnocchi`
themselves in the meantime if need be.

Change-Id: I0bae6dfbbee9f63506c89bd6b392e7be07fd5930