Filehooks test configuration on permissions branch breaks integration tests

As of commit 16400772f29f3d7bd45e91348b5dd4b48e405386, in filehooks/conf/conf.test.ini the urls use the names of the docker containers used in production. The containers used for the integration test use the same names with the added postfix _integration, so that they can run in parallel.

If this change was unintentional, it suffices to changes the urls referencing container names to look like this: http://sharing_gitlab_integration:80 (just add _integration at the end).

If the current version of this config is used, then we should just create an extra config file for integration tests to avoid conflicts.