Apparently, I managed to corrupt an SQLite DB when `git-annex get` ran out of space.  This prevents git-annex operations from
working at all now.

For example:

    % git annex find --in .
    sqlite worker thread crashed: SQLite3 returned ErrorError while attempting to perform prepare "SELECT null from content limit 1": no such table: content
    git-annex: sqlite query crashed

One of the few mentions of SQLite being used is in incremental fsck
([[design/caching_database]]).  I did run incremental fsck in
another repository a few days before this.  The fsck finished
without issues, so I'd be happy with a solution that involves simply
deleting the DB or something.

- git-annex version: 6.20160527-gb7d4774
- All repositories/remotes: version 5, indirect
