net-snmp: fix inbound firewall rule support

Commit ae5ee6ba6c added support for inbound
firewall rule support but some corner cases were not covered.

In case net-snmp is started and the network interface is already up
the procd firewall rule is created but not applied by fw3 as
service_started calling procd_set_config_changed firewall was missing.

When stopping net-snmp clean up the net-snmp inbound firewall rules in
iptables by calling procd_set_config_changed firewall in stop_service
which will trigger fw3 to remove the inbound firewall rules.

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

net/net-snmp/files/snmpd.init

@@ -325,6 +325,7 @@ start_service() {
 
 stop_service() {
 	[ -f "$CONFIGFILE" ] && rm -f "$CONFIGFILE"
+	procd_set_config_changed firewall
 }
 
 service_triggers(){
@@ -337,3 +338,7 @@ service_triggers(){
 
 	procd_add_reload_trigger 'snmpd'
 }
+
+service_started() {
+	procd_set_config_changed firewall
+}