R1:2a815e0715da

Fix a PhutilOpaqueEnvelope issue with `bin/storage dump`

Summary: We need to open the envelope here.

Test Plan: Ran `bin/storage dump` without errors.

Reviewers: vrana, btrahan

Reviewed By: vrana

CC: aran

Differential Revision: https://secure.phabricator.com/D3315