remove /tmp/resolv.conf.auto when ifup -a is called so that any old dns servers no longer in the config get cleared

SVN-Revision: 13082

package/base-files/files/sbin/ifdown

@@ -4,6 +4,7 @@
 . /etc/functions.sh
 [ $# = 0 ] && { echo "  $0 <group>"; exit; }
 [ "x$1" = "x-a" ] && {
+	[ -e "/tmp/resolv.conf.auto" ] && rm /tmp/resolv.conf.auto
 	config_cb() {
 		[ interface != "$1" -o -z "$2" ] || eval "$0 $2"
 	}