Add serial number for sw-chichlet-[1-3] switchs

This Merge Request just put the serial number of the Cisco switches of Lille (sw-chiclet-[1-3]) in the refrepo, inside the serial field.

data/grid5000/sites/lille/network_equipments/sw-chiclet-1.json

@@ -344,6 +344,7 @@
     }
   ],
   "model": "cisco 93180YC-EX",
+  "serial": "FDO20401BDX",
   "site": "lille",
   "snmp_community": "public",
   "type": "network_equipment",