Previously this would fail if you attempted to restore the database:

```
RAILS_ENV=test bundle exec rake db:reset
RAILS_ENV=test bundle exec rake gitlab:backup:db:create
RAILS_ENV=test bundle exec rake gitlab:db:drop_tables
RAILS_ENV=test bundle exec rake gitlab:backup:db:restore
```

The last step would attempt to read `backup_information.yml` and fail
because the file isn't generated in the `gitlab:backup:db:create`
task. We can disable the reading of that file since it's only needed
in the `gitlab:backup:create` task.

In addition, the third step is optional. Since the `feature_flags`
table does not exist, the feature flag check that happened in the last
step would fail.

Changelog: fixed