add /etc/firewall.user to be backed up becuase it is an example in /etc/config/firewall

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@12326 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/base-files/files/sbin/sysupgrade

@@ -44,7 +44,7 @@ EOF
 
 add_uci_conffiles() {
 	local file="$1"
-	find /etc/config /etc/passwd /etc/group /etc/dropbear > "$file"
+	find /etc/config /etc/passwd /etc/group /etc/dropbear /etc/firewall.user > "$file"
 	return 0
 }