This commit fixes two problems:

1. If the object type is disabled but object storage is enabled (as it
is in Cloud Native GitLab), previously the URL blocker would attempt
to drill into the endpoint. We now check that the type is also enabled.

2. Due to a Settingslogic bug
(#286873), the use of
`default` anywhere causes `Hash#default` to be overriden for the
`Settingslogic` class. If `connection` field `connection.endpoint` is
omittted from object storage config, this previously would result in
an error:

```
ArgumentError: wrong number of arguments (given 1, expected 0)>
```

We need to call `to_h` because we define `default` as a Gitaly storage
name in GitLab Charts.

Relates to #357340

Changelog: fixed