[gen] fix for failed valid:schema check

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

input/grid5000/ipv6.yaml

-ipv6:
-  site-indexes:
-    grenoble: 1
-    lille: 2
-    luxembourg: 3
-    lyon: 4
-    nancy: 5
-    nantes: 6
-    rennes: 7
-    sophia: 8

lib/refrepo/input_loader.rb

@@ -107,6 +107,17 @@ def add_kavlan_ips(h)
   end
 end
 
+$ipv6_site_indexes = {
+  'grenoble' => 1,
+  'lille' => 2,
+  'luxembourg' => 3,
+  'lyon' => 4,
+  'nancy' => 5,
+  'nantes' => 6,
+  'rennes' => 7,
+  'sophia' => 8,
+}
+
 def add_ipv6(h)
   # for each node
   h['sites'].each_pair do |site_uid, hs|
@@ -121,7 +132,7 @@ def add_ipv6(h)
             if not ip4.nil?
               # compute and assign IPv6 based on IPv4
               ip6 = '2001:660:4406:'
-              ip6 += '%x' % h['ipv6']['site-indexes'][site_uid]
+              ip6 += '%x' % $ipv6_site_indexes[site_uid]
               ip6 += '00:'
               ip6 += '%x::' % ((ip4.split('.')[2].to_i & 0b1111) + 1)
               ip6 += '%x' % (ip4.split('.')[3].to_i)