[Security] [ACL] Fix finding ACLs from ObjectIdentity's with different types

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        | 

If more than one ObjectIdentity with different Type (Class name) is given to AclProvider::findAcls() it would throw an exception stating that it could not find the ACLs

This fixes this issue which was introduced in 2.2.0-RC3 - see commit 3c3a90b9e5c78f89027169a33e80cfa76b6f6c62

/cc @iBiryukov @schmittjoh