Lower the priority of message when failing to remove a file from the Catalogue

Summary

Currently we log an ERROR when the frontend is processing a delete request and it is unable to remove the file from the Catalogue. We do not differentiate between the possible scenarios that can cause the failure, some should be reported as INFO (file in queued for archive but not yet archived) some should be reported as ERROR (we were not able to connect to the Catalogue due to network issues). For now we will modify the severity of the log message to WARN.