Add bsc.es to resolve domain names

Reviewed-by: Aleix Boné <abonerib@bsc.es>
Reviewed-by: Aleix Roca Nonell <aleix.rocanonell@bsc.es>

m/tent/configuration.nix

@@ -26,6 +26,7 @@
 
     # Only BSC DNSs seem to be reachable from the office VLAN
     nameservers = [ "84.88.52.35" "84.88.52.36" ];
+    search = [ "bsc.es" ];
     defaultGateway = "10.0.44.1";
   };