packer/outscale: add overwrite_existing config param

Author: jfbus

images/capi/packer/outscale/packer.json

@@ -2,6 +2,8 @@
   "builders": [
     {
       "access_key": "{{ user `access_key` }}",
+      "force_delete_snapshot": "{{user `overwrite_existing`}}",
+      "force_deregister": "{{user `overwrite_existing`}}",
       "global_permission": "{{ user `global_permission` }}",
       "omi_account_ids": [
         "{{ user `account_id` }}"
@@ -121,6 +123,7 @@
     "kubernetes_series": null,
     "kubernetes_source_type": null,
     "omi_name": "{{user `build_name`}}-kubernetes-{{user `kubernetes_semver`}}-{{isotime `2006-01-02`}}",
+    "overwrite_existing": "false",
     "owner": "Outscale",
     "region": "{{env `OSC_REGION`}}",
     "runc_sha256": null,