Don't send Hellos and Updates to new neighbours.

This slows down initial convergence, but avoids a broadcast burst
at boot.  Thanks to Teco Boot for pointing this out.

(cherry picked from commit b66c1733)

neighbour.c

@@ -177,20 +177,6 @@ update_neighbour(struct neighbour *neigh, int hello, int hello_interval)
             rc = 1;
     }
 
-    /* Make sure to give neighbours some feedback early after association */
-    if((neigh->reach & 0xBF00) == 0x8000) {
-        /* A new neighbour */
-        send_hello(neigh->ifp);
-    } else {
-        /* Don't send hellos, in order to avoid a positive feedback loop. */
-        int a = (neigh->reach & 0xC000);
-        int b = (neigh->reach & 0x3000);
-        if((a == 0xC000 && b == 0) || (a == 0 && b == 0x3000)) {
-            /* Reachability is either 1100 or 0011 */
-            send_self_update(neigh->ifp);
-        }
-    }
-
     return rc;
 }