R1:5f170847caa8

Throw a more tailored error when a `storage upgrade` patch can't access a database

Summary: Fixes T8762.

Test Plan: Ran `bin/storage upgrade --namespace ... --user limited`, saw a more specific error.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T8762

Differential Revision: https://secure.phabricator.com/D15080