Fix _ComputeNics to include network slot

This bug was introduced after rebasing master branch.

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>
Reviewed-by: Iustin Pop <iustin@google.com>

lib/cmdlib.py

@@ -9577,7 +9577,8 @@ def _ComputeNics(op, cluster, default_ip, cfg, proc):
     check_params = cluster.SimpleFillNIC(nicparams)
     objects.NIC.CheckParameterSyntax(check_params)
-    nics.append(objects.NIC(mac=mac, ip=nic_ip, nicparams=nicparams))
+    nics.append(objects.NIC(mac=mac, ip=nic_ip,
+                            network=net, nicparams=nicparams))
   return nics