net/mwan3: add init script to enable/disable mwan3 globally

Adding a init script to "/etc/init.d/" introduce the possibility to
enable/disable mwan3 globally.

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

net/mwan3/files/etc/hotplug.d/iface/15-mwan3

@@ -12,15 +12,18 @@ if [ "$ACTION" == "ifup" ]; then
         [ -n "$DEVICE" ] || exit 3
 fi
 
-mwan3_lock
-mwan3_set_connected_iptables
-mwan3_unlock
-
 config_load mwan3
+config_get_bool enabled globals 'enabled' '0'
+[ ${enabled} -gt 0 ] || exit 0
+
 config_get enabled $INTERFACE enabled 0
 config_get initial_state $INTERFACE initial_state "online"
 [ "$enabled" == "1" ] || exit 0
 
+mwan3_lock
+mwan3_set_connected_iptables
+mwan3_unlock
+
 if [ "$ACTION" == "ifup" ]; then
 	config_get family $INTERFACE family ipv4
 	if [ "$family" = "ipv4" ]; then