[zebra] Only announce connected routes if link is detected

Need to check both IFF_UP and IFF_RUNNING if link-detect is enabled,
before announcing routes.
diff --git a/zebra/connected.c b/zebra/connected.c
index ad3e960..f3e5396 100644
--- a/zebra/connected.c
+++ b/zebra/connected.c
@@ -86,7 +86,7 @@
 
       zebra_interface_address_add_update (ifp, ifc);
 
-      if (if_is_up(ifp))
+      if (if_is_operative(ifp))
         {
           if (ifc->address->family == AF_INET)
 	    connected_up_ipv4 (ifp, ifc);