package/busybox: fix avahi-autoipd error message

When using a combination of udhcpc and avahi-autoipd in case of receiving IP
from a DHCP server, the following message can be seen:
"Failed to kill daemon: No such file or directory".
Add a check for a running avahi-autoipd to fix this issue.

Signed-off-by: Lukasz Tekieli <tekieli.lukasz@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 3c5ca644ef8dbcccbc40fc3fc56b74bc54782ae4)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/busybox/udhcpc.script

@@ -42,19 +42,19 @@ case "$1" in
 		rm -f $TMPFILE
 
 		if [ -x /usr/sbin/avahi-autoipd ]; then
-			/usr/sbin/avahi-autoipd -k $interface
+			/usr/sbin/avahi-autoipd -c $interface && /usr/sbin/avahi-autoipd -k $interface
 		fi
 		;;
 
 	leasefail|nak)
 		if [ -x /usr/sbin/avahi-autoipd ]; then
-			/usr/sbin/avahi-autoipd -wD $interface --no-chroot
+			/usr/sbin/avahi-autoipd -c $interface || /usr/sbin/avahi-autoipd -wD $interface --no-chroot
 		fi
 		;;
 
 	renew|bound)
 		if [ -x /usr/sbin/avahi-autoipd ]; then
-			/usr/sbin/avahi-autoipd -k $interface
+			/usr/sbin/avahi-autoipd -c $interface && /usr/sbin/avahi-autoipd -k $interface
 		fi
 		/sbin/ifconfig $interface $ip $BROADCAST $NETMASK
 		if [ -n "$ipv6" ] ; then