[nancy/grouille] Disable disk reservation

data/grid5000/sites/nancy/clusters/grouille/nodes/grouille-1.json

@@ -220,7 +220,6 @@
       "firmware_version": "D3DJ004",
       "interface": "SATA",
       "model": "MTFDDAK960TDT",
-      "reservation": true,
       "size": 960197124096,
       "storage": "SSD",
       "vendor": "Micron"