[CBM] Failure to backup Query UDFs in mixed mode

# ./cbbackupmgr backup -a /backup1 -r my_backup -c http://localhost:8091 -u Administrator -p password --purge

Backing up to '2021-09-03T15_55_09.452493716-07_00'

Transferring Query metadata                                                                                          0 items / 0B

[                                                                                                                         ] 0.13%

Error backing up cluster: received an unexpected 404 status executing 'GET' request to '/api/v1/backup' check the logs for more details

| Transfer

| --------

| Status | Avg Transfer Rate | Started At                        | Finished At                     | Duration |

| Failed | 0B                | Fri, 03 Sep 2021 15:55:09 -0700/s | Fri, 03 Sep 2021 15:55:09 -0700 | 294ms    |