[nantes] move ntp site to srv-3

data/grid5000/sites/nantes/servers/srv-2.json

 {
-  "alias": [
-    "ntp"
-  ],
   "kind": "physical",
   "network_adapters": {
     "bmc": {

data/grid5000/sites/nantes/servers/srv-3.json

 {
+  "alias": [
+    "ntp"
+  ],
   "kind": "physical",
   "network_adapters": {
     "bmc": {

input/grid5000/sites/nantes/servers/servers.yaml

@@ -26,8 +26,6 @@ srv-data:
 
 srv-2:
   kind: physical
-  alias:
-    - ntp
   warranty: 2019-11
   serial: JP2YG5J
   network_adapters:
@@ -40,6 +38,8 @@ srv-2:
 
 srv-3:
   kind: physical
+  alias:
+    - ntp
   warranty: 2019-11
   serial: 9TJRXW2
   network_adapters: