A way to route plantuml requests through gitea to localhost

Hi there,

thanks for this great tool. I’ve setup plantuml integration into Gitea, following mainly the official guide from here Customizing Gitea - Docs. I’ve first setup my own plantuml server locally reachable at http://localhost:8000/plantuml on the server. This hasn’t worked because the rendered image couldn’t be downloaded from “the world”. Then, I’ve made the plantuml server listinening on 0.0.0.0 and reachable at https://my.gitea.server/plantuml what fixed the issue. However, is it possible to route the request say https://my.gitea.server/plantuml/img/SoMeEncodeDString through gitea to the local plantuml server? I want to avoid to expose the https://my.gitea.server/plantuml endpoint, which is served by the plantuml minimal server without any authentication and not the gitea server. It would be great if for example only logged in users can reach the plantuml endpoint.