Describe the bug

auth_oauth2.verify_aud is an attribute associated to a single resource server in the oauth2 backend. However, this backend also supports multiple resource servers. However, this attribute is not available for each resource server declared under `auth_oauth2.resource_servers".

Reproduction steps

Add the following configuration entry has no effect:
auth_oauth2.resource_servers.1.verify_aud = false

Expected behavior

Use the value configured in auth_oauth2.resource_servers.1.verify_aud or else default to auth_oauth2.verifry_aud.

Additional context

No response