Sharepoint DLS+Certificate auth results in PermissionsMissing error

## Bug Description
When using both Certificate Auth and with DLS enabled for Sharepoint Online, I'm hitting a sync error:

```
Sync failure: PermissionsMissing: Received Unauthorized response for https://enterprisesearch.sharepoint.com/sites/Sean'sTeamSite/_api/web/roleassignments?$expand=Member/users,RoleDefinitionBindings.
```

### To Reproduce
1. Create an SPO connector on 8.17.2+
2. use Certificate (not secret) auth
3. enable DLS
4. run a sync
5. see a failure

## Expected behavior
choosing Certificate vs secret auth, or enabling vs disabling DLS, shouldn't cause any issues

## Environment
8.17.3 (any version since Certificate Auth was added as an option)