ip: change icmp4 throttle

traceroute sends 3 packets rapidly that triggers and depends on ICMP error
generation. The current ICMP4 throttle setting at 1-e3 throttles the last
ICMP error and makes traceroute sit in a timeout.

Type: fix
Change-Id: Ie886303600ad0374dcb6ae311e949154727a93d2
Signed-off-by: Ole Troan <otroan@employees.org>
diff --git a/src/vnet/ip/icmp4.c b/src/vnet/ip/icmp4.c
index 562cbce..7dc21c5 100644
--- a/src/vnet/ip/icmp4.c
+++ b/src/vnet/ip/icmp4.c
@@ -590,7 +590,7 @@
   vlib_thread_main_t *tm = &vlib_thread_main;
   u32 n_vlib_mains = tm->n_vlib_mains;
 
-  throttle_init (&icmp_throttle, n_vlib_mains, THROTTLE_BITS, 1e-3);
+  throttle_init (&icmp_throttle, n_vlib_mains, THROTTLE_BITS, 1e-5);
 
   return 0;
 }