HTTP 404 when running :ideSetupP2

I am in the process of migrating a project from net.ltgt.apt-eclipse to com.diffplug.eclipse.apt, and I'm running into an issue when running the :ideSetupP2 task:

```
FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':ideSetupP2'.
> http://:8081/nexus/repository/goomph-p2-bootstrap//goomph-p2-bootstrap-4.7.2.zip
received http code 404
```

I do have this asset, but it's at a different path:

```
http://:8081/nexus/repository/thirdparty/com/diffplug/gradle/goomph-p2-bootstrap/4.7.2/goomph-p2-bootstrap-4.7.2.zip
```

Is there a way to configure which path the plugin uses?