fix: call save iptables handler using correct name

tasks/configure_iptables_external.yml

@@ -9,4 +9,4 @@
     protocol: "{{ item.protocol | default('tcp') }}"
     source: "{{ item.source }}"
   loop: "{{ vault_iptables_external }}"
-  notify: save iptables rules (Debian)
+  notify: save iptables rules