busybox: udhcpc script: suppress useless error message

Suppress the following error:

route: SIOCDELRT: No such process

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/busybox/udhcpc.script

@@ -40,7 +40,7 @@ case "$1" in
 
 		if [ -n "$router" ] ; then
 			echo "deleting routers"
-			while route del default gw 0.0.0.0 dev $interface ; do
+			while route del default gw 0.0.0.0 dev $interface 2> /dev/null; do
 				:
 			done