mwan3: add migration script for flush_conntrack config

Signed-off-by: Florian Eckert <fe@dev.tdt.de>

net/mwan3/files/etc/uci-defaults/mwan3-migrate-flush_conntrack

@@ -0,0 +1,26 @@
+#!/bin/sh
+
+. /lib/functions.sh
+
+mwan3_migrate_flush_conntrack() {
+	local iface="$1"
+
+	config_get value "${iface}" flush_conntrack
+	case $value in
+		always)
+			uci_remove mwan3 "$iface" flush_conntrack
+			uci_add_list mwan3 "$iface" flush_conntrack ifup
+			uci_add_list mwan3 "$iface" flush_conntrack ifdown
+			;;
+		never)
+			uci_remove mwan3 "$iface" flush_conntrack
+			;;
+	esac
+
+	uci_commit mwan3
+}
+
+config_load mwan3
+config_foreach mwan3_migrate_flush_conntrack interface
+
+exit 0