igw: use api_port variable for firewall port setting

Don't hard code api port because it might be overridden by the user.

Signed-off-by: Mike Christie <mchristi@redhat.com>
(cherry picked from commit e2f1f81de4)

roles/ceph-infra/tasks/configure_firewall.yml

@@ -168,9 +168,9 @@
   tags:
     - firewall
 
-- name: open iscsi ports
+- name: open iscsi api ports
   firewalld:
-    port: "5000/tcp"
+    port: "{{ api_port | default(5000) }}/tcp"
     zone: "{{ ceph_iscsi_firewall_zone }}"
     source: "{{ public_network }}"
     permanent: true