Routing rules not taking effect for docker when running with external db

Routing rules for Docker repos are not taking effect when running with external DB (Postgres or H2).

To reproduce:

1. Nexus instance running with external DB (Postgres or H2).

2. Configure a blocking routing rule with the following matcher:

.*cloudbees.*

Test the matcher and confirm it will block any path containing "cloudbees".

3. Apply this rule to a docker hub proxy repo.

4. Attempt to pull a cloudbees image via the proxy e.g. cloudbees/juxr and confirm that the pull succeeds.

Expected

Routing rules should take effect for Docker repos when running Nexus with an external DB. For this test case, the pull request should have been blocked.

Furthermore, this has only been reported and tested with Docker, so Dev should also confirm if this issues exists with other formats as well.