[dev] remove ipv6 info from root

data/grid5000/grid5000.json

 {
-  "ipv6": {
-    "site-indexes": {
-      "grenoble": 1,
-      "lille": 2,
-      "luxembourg": 3,
-      "lyon": 4,
-      "nancy": 5,
-      "nantes": 6,
-      "rennes": 7,
-      "sophia": 8
-    }
-  },
   "type": "grid",
   "uid": "grid5000"
 }
\ No newline at end of file

lib/refrepo/gen/reference-api.rb

@@ -112,6 +112,9 @@ def generate_reference_api
     # remove kavlan information for now
     global_hash.delete('vlans')
 
+    # also remove ipv6 info
+    global_hash.delete('ipv6')
+    
     grid_path = Pathname.new(refapi_path)
     grid_path.mkpath()