firewall-defaults: remove advanced section from firewall configuration

Some of the options are now part of the defaults section. Some are
configured in /etc/sysctl.conf.

The openwrt defaults are sane. We use these from now on.

Addresses: freifunk-berlin/firmware#465

defaults/freifunk-berlin-firewall-defaults/uci-defaults/freifunk-berlin-firewall-defaults

@@ -118,11 +118,6 @@ uci set firewall.$RULE.proto=tcp
 uci set firewall.$RULE.target=ACCEPT
 uci set firewall.$RULE.src=freifunk
 
-ADVANCED="$(uci add firewall advanced)"
-uci set firewall.$ADVANCED.tcp_westwood=1
-uci set firewall.$ADVANCED.tcp_ecn=0
-uci set firewall.$ADVANCED.ip_conntrack_max=8192
-
 FORWARDING="$(uci add firewall forwarding)"
 uci set firewall.$FORWARDING.dest=wan
 uci set firewall.$FORWARDING.src=freifunk