[orsay] Updated latitude & longitude values.

data/grid5000/sites/orsay/orsay.json

 {
   "description": "",
   "email_contact": null,
-  "latitude": null,
+  "latitude": 48.7,
   "location": "Orsay, France",
-  "longitude": null,
+  "longitude": 2.2,
   "name": "Orsay",
   "security_contact": null,
   "sys_admin_contact": null,