mwan3: reload unreachable/blackhole rules on hotplug

when the network procd service restarts, it flushes the ip rules. We
need to add these rules back. Since hotplug events are triggered when
the networks come back online, adding this call to the hotplug script
is the most convenient place to refresh the rules.

Signed-off-by: Aaron Goodman <aaronjg@stanford.edu>

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

@@ -74,6 +74,7 @@ case "$ACTION" in
 		mwan3_set_iface_hotplug_state $INTERFACE "$status"
 		if [ "$MWAN3_STARTUP" != 1 ]; then
 			mwan3_create_iface_route $INTERFACE $DEVICE
+	                mwan3_set_general_rules
 			[ "$status" = "online" ] && mwan3_set_policies_iptables
 		fi
 		[ "$ACTION" = ifup ] && procd_running mwan3 "track_$INTERFACE" && procd_send_signal mwan3 "track_$INTERFACE" USR2