[source] igmpproxy: remove firewall rules when service is stopped

[LEDE Commits]

jow pushed a commit to source.git, branch lede-17.01:
https://git.lede-project.org/c315843f882b1eddb5af4cbc372ce1f41105eb65

commit c315843f882b1eddb5af4cbc372ce1f41105eb65
Author: Hans Dedecker <dedeckeh at gmail.com>
AuthorDate: Mon Nov 13 22:33:48 2017 +0100

    igmpproxy: remove firewall rules when service is stopped
    
    Remove multicast routing firewall rules when the igmpproxy is stopped by
    triggering a firewall config change.
    Keeping the firewall open from the wan for igmp and udp multicast is not
    desired when the igmpproxy service is inactive.
    
    Signed-off-by: Hans Dedecker <dedeckeh at gmail.com>
    (cherry picked from commit 31ebbe34ccc066c212ef20de0856ab3a428fb801)
---
 package/network/services/igmpproxy/Makefile             | 2 +-
 package/network/services/igmpproxy/files/igmpproxy.init | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/package/network/services/igmpproxy/Makefile b/package/network/services/igmpproxy/Makefile
index d07fe66..38efabe 100644
--- a/package/network/services/igmpproxy/Makefile
+++ b/package/network/services/igmpproxy/Makefile
@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=igmpproxy
 PKG_VERSION:=0.1
-PKG_RELEASE:=9
+PKG_RELEASE:=10
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=@SF/igmpproxy
diff --git a/package/network/services/igmpproxy/files/igmpproxy.init b/package/network/services/igmpproxy/files/igmpproxy.init
index 9f4e51a..4038545 100644
--- a/package/network/services/igmpproxy/files/igmpproxy.init
+++ b/package/network/services/igmpproxy/files/igmpproxy.init
@@ -132,3 +132,7 @@ start_service() {
 service_started() {
 	procd_set_config_changed firewall
 }
+
+stop_service() {
+	procd_set_config_changed firewall
+}