TOC links not working correctly with custom IDs

Hi, many thanks for the contribution in &1378 (closed) and https://gitlab.com/gitlab-org/gitlab-ce/issues/64070

Now finally TOC from adoc document works. However, there is still some issue, if a section has a custom id defined, the link does not work:

Example: Document: https://gitlab.com/ID4me/documentation/blob/master/id4ME%20Relying%20Party%20Implementation%20Guide.adoc

Link from TOC: 3.2. Relying Party performs dynamic client registration at Identity Authority

https://gitlab.com/ID4me/documentation/blob/master/id4ME%20Relying%20Party%20Implementation%20Guide.adoc#dynamic-client-registration

Definition in adoc:

[[dynamic-client-registration]]
=== Relying Party performs dynamic client registration at Identity Authority