[grenoble] network - skinovis2-admin-01 has no SSH so put it as 'not managed by us'

data/grid5000/sites/grenoble/network_equipments/skinovis2-admin-01.json

@@ -113,7 +113,7 @@
       "rate": 1000000000
     }
   ],
-  "managed_by_us": true,
+  "managed_by_us": false,
   "model": "Dell PowerConnect 6248",
   "serial": "nil",
   "site": "grenoble",

input/grid5000/sites/grenoble/networks/skinovis2-admin-01.yaml

@@ -4,7 +4,8 @@ skinovis2-admin-01:
   warranty: 2024-12-01
   serial: nil
   kind: switch
-  managed_by_us: true
+  # this switch has no SSH for now
+  managed_by_us: false
   site: grenoble
   snmp_community: public
   ip: 172.17.31.244