fix cross cluster backup restore

[boddumanohar]

currently when I have 2 cluster and when I import an backup into a target cluster I get this error

# sbctl backup import /app/backup1.json --cluster-id 81932010-8c06-4acd-b14a-51f5c3fca425
Imported 0 backup(s)
True

testing

# export SRC_CLUSTER=bfa260ce-06a7-4bcb-a843-813d0be633af
# export TARGET_CLUSTER=81932010-8c06-4acd-b14a-51f5c3fca425


/app# sbctl backup export --lvol pvc-7fe87aa9-c6c3-4dc6-9baf-94696b6ccec7 --cluster  $SRC_CLUSTER -o backup1.json
Exported 1 backup(s) to backup1.json
True
/app# sbctl backup import /app/backup1.json --cluster-id $TARGET_CLUSTER
Imported 1 backup(s)
True
/app#