Description of problem:

oc-mirror will hit panic when use v2 and mirror from disk to registry

Version-Release number of selected component (if applicable):

How reproducible:

always

Steps to Reproduce:

1. Create  imageset that we are using:
cat config.yaml 
apiVersion: mirror.openshift.io/v1alpha2
kind: ImageSetConfiguration
mirror:
  platform:
    channels:
      - name: stable-4.13
        minVersion: 4.13.13
        maxVersion: 4.13.13
    graph: true
2. Mirror to disk by command :
`oc-mirror --config config.yaml file://out  --v2`
3. Mirror from disk to registry by command:
`oc-mirror --config config.yaml  --from out/working-dir/ docker://ec2-18-217-139-237.us-east-2.compute.amazonaws.com:5000/ocpv2  --v2`

Actual results:
oc-mirror   --from out/working-dir/ docker://ec2-18-217-139-237.us-east-2.compute.amazonaws.com:5000/ocpv2  --v2
--v2 flag identified, flow redirected to the oc-mirror v2 version. PLEASE DO NOT USE that. V2 is still under development and it is not ready to be used. 
2023/11/06 03:10:19  [ERROR]  : use the --config flag it is mandatory 
[root@preserve-fedora36 1106]# oc-mirror --config config.yaml  --from out/working-dir/ docker://ec2-18-217-139-237.us-east-2.compute.amazonaws.com:5000/ocpv2  --v2
--v2 flag identified, flow redirected to the oc-mirror v2 version. PLEASE DO NOT USE that. V2 is still under development and it is not ready to be used. 
panic: runtime error: index out of range [1] with length 1
 
goroutine 1 [running]:
github.com/openshift/oc-mirror/v2/pkg/cli.(*ExecutorSchema).Complete(0xc000c28a80, {0xc00012cd20, 0x1, 0x0?})
/go/src/github.com/openshift/oc-mirror/vendor/github.com/openshift/oc-mirror/v2/pkg/cli/executor.go:330 +0x1a18
github.com/openshift/oc-mirror/v2/pkg/cli.NewMirrorCmd.func1(0xc000005500?, {0xc00012cd20, 0x1, 0x6})
/go/src/github.com/openshift/oc-mirror/vendor/github.com/openshift/oc-mirror/v2/pkg/cli/executor.go:137 +0xfd
github.com/spf13/cobra.(*Command).execute(0xc000005500, {0xc000052080, 0x6, 0x6})
/go/src/github.com/openshift/oc-mirror/vendor/github.com/spf13/cobra/command.go:944 +0x847
github.com/spf13/cobra.(*Command).ExecuteC(0xc000005500)
/go/src/github.com/openshift/oc-mirror/vendor/github.com/spf13/cobra/command.go:1068 +0x3bd
github.com/spf13/cobra.(*Command).Execute(0x0?)
/go/src/github.com/openshift/oc-mirror/vendor/github.com/spf13/cobra/command.go:992 +0x19
main.main()
/go/src/github.com/openshift/oc-mirror/cmd/oc-mirror/main.go:10 +0x1e

Expected results:

No panic

Additional info: