AppIntegrationTest is not using src/test/resources but src/main/resources for the gretty server test instance

So I have a properties file in my project in src/main/resources which has some configuration options for my web application. For testing I made some changes in the properties file and put it in src/test/resources. But the problem is that the server instance from the AppBeforeIntegrationTestTask is using the resources of the main folder.

Since this is obviously not working: How is the workflow to start the server instance for integration testing with a modified properties file?

Gretty 3.0.1