Remove id field which is not part of this api (Azure#22723)

Author: Dylan-MSFT

specification/sql/resource-manager/Microsoft.Sql/stable/2014-04-01/examples/ServerAdminCreateUpdate.json

@@ -6,7 +6,6 @@
     "administratorName": "activeDirectory",
     "api-version": "2014-04-01",
     "properties": {
-      "id": "/subscriptions/00000000-1111-2222-3333-444444444444/resourceGroups/sqlcrudtest-4799/providers/Microsoft.Sql/servers/sqlcrudtest-6440/administrators/activeDirectory",
       "name": "activeDirectory",
       "properties": {
         "administratorType": "ActiveDirectory",