Notify when ip address changes

src/freedombone-installer

@@ -2600,6 +2600,9 @@ function update_dynamic_dns {
 function webadmin_monitor_ip_changes {
     curr_ipv4=$(get_external_ipv4_address)
     if [[ "$curr_ipv4" != "$webadmin_ipv4_address" ]]; then
+        if [ "$webadmin_ipv4_address" ]; then
+            /usr/local/bin/${PROJECT_NAME}-notification -s "[${PROJECT_NAME}] Dynamic DNS" -m "IP address changed from $webadmin_ipv4_address to $curr_ipv4"
+        fi
         webadmin_ipv4_address="$curr_ipv4"
         update_dynamic_dns
     fi