CA-56594: "xe host-backup" now uses the new helper function, for symmetry with other HTTP ops
CA-56594: "xe host-backup" now uses the new helper function, for symmetry with other HTTP ops

NB "xe host-backup" worked before this change.

Signed-off-by: David Scott <63c9eb0ea83039690fefa11afe17873ba8278a56@eu.citrix.com>

djs55/xcp-networkd,simonjbeaumont/xcp-rrdd,djs55/squeezed,sharady/xcp-networkd,koushikcgit/xcp-rrdd,djs55/xcp-networkd,simonjbeaumont/xcp-rrdd,koushikcgit/xcp-rrdd,djs55/xcp-rrdd,koushikcgit/xcp-networkd,koushikcgit/xcp-rrdd,djs55/xcp-rrdd,robhoes/squeezed,sharady/xcp-networkd,johnelse/xcp-rrdd,koushikcgit/xcp-networkd,johnelse/xcp-rrdd