[nancy] remove the IP name backup-local (vm no more used)

data/grid5000/sites/nancy/servers/backup-local.json

-{
-  "kind": "virtual",
-  "network_adapters": {
-    "default": {
-      "ip": "172.16.79.158"
-    }
-  },
-  "type": "server",
-  "uid": "backup-local"
-}
\ No newline at end of file

input/grid5000/sites/nancy/servers/virtual.yaml

@@ -86,9 +86,6 @@ icinga:
 kwapi:
   kind: virtual
   network_adapters: {default: {ip: 172.16.79.54}}
-backup-local:
-  kind: virtual
-  network_adapters: {default: {ip: 172.16.79.158}}
 jenkins:
   kind: virtual
   network_adapters: {default: {ip: 172.16.79.160}}