add a site seed

site.conf

@@ -2,6 +2,7 @@
     hostname_prefix = 'ffs-',
     site_name = 'Freifunk Stuttgart',
     site_code = 'ffs',
+    site_seed = '0711ff0711ff0711ff0711ff0711ff0711ff0711ff0711ff0711ff0711ff0711',
 
     prefix4 = '172.21.0.0/18',
     prefix6 = 'fd21:711::/64',
@@ -122,6 +123,7 @@
                 },
             },
         },
+
         bandwidth_limit = {
             -- Default upload limit (kbit/s).
             egress = 500,