Unable to create a new repository using the REST API after migrating to JBoss BRMS 6.1

Issue

Previously on BRMS 6.0.3 we were able to create a repository using the following REST request:

$ curl --user 'jesuino:redhat2014!' --data '{"name":"new_repo", "requestType":"new"}' -H 'Content-type: application/json' -X POST http://localhost:8080/business-central/rest/repositories
{"jobId":"1433969234731-2","status":"ACCEPTED","repository":{"name":"new_repo","description":null,"userName":null,"password":null,"requestType":"new","gitURL":null}}

However, starting on BPM Suite 6.1, it is not possible to start a new repository using the exactly same command, it returns HTTP 404 code. What's wrong?