##### SUMMARY
If a host has port set to a usermacro, the host is created successfully. On the next run, the update fails with `ValueError: invalid literal for int() with base 10: {$MACRO}`.

Tested with the latest `zabbix_host` from git.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
zabbix_host

##### ANSIBLE VERSION
latest

##### CONFIGURATION
Not relevant.

##### OS / ENVIRONMENT
Not relevant.

##### STEPS TO REPRODUCE
Have a host definition with usermacro used for port in an interface. Create the host via Ansible, then run the playbook again.

##### EXPECTED RESULTS
Success (reported as no change).

##### ACTUAL RESULTS

```paste below
Traceback (most recent call last):
  File \"/home/ansible/.ansible/tmp/ansible-tmp-1571042967.61-236562069605480/AnsiballZ_zabbix_host.py\", line 114, in <module>
    _ansiballz_main()
  File \"/home/ansible/.ansible/tmp/ansible-tmp-1571042967.61-236562069605480/AnsiballZ_zabbix_host.py\", line 106, in _ansiballz_main
    invoke_module(zipped_mod, temp_path, ANSIBALLZ_PARAMS)
  File \"/home/ansible/.ansible/tmp/ansible-tmp-1571042967.61-236562069605480/AnsiballZ_zabbix_host.py\", line 49, in invoke_module
    imp.load_module(__main__, mod, module, MOD_DESC)
  File \"/tmp/ansible_zabbix_host_payload_7ml4r2/__main__.py\", line 857, in <module>
  File \"/tmp/ansible_zabbix_host_payload_7ml4r2/__main__.py\", line 817, in main
  File \"/tmp/ansible_zabbix_host_payload_7ml4r2/__main__.py\", line 479, in check_all_properties
  File \"/tmp/ansible_zabbix_host_payload_7ml4r2/__main__.py\", line 437, in check_interface_properties
ValueError: invalid literal for int() with base 10: {$MACRO}
```

tls_psk = module.params['tls_psk']
    tls_issuer = module.params['ca_cert']
    tls_subject = module.params['tls_subject']
    inventory_zabbix = module.params['inventory_zabbix']
    status = module.params['status']
    state = module.params['state']
    timeout = module.params['timeout']
    interfaces = module.params['interfaces']
    force = module.params['force']
    proxy = module.params['proxy']
    
    status = 1 if status == "disabled" else 0
    zbx = None
    
    try:
        zbx = ZabbixAPI(server_url, timeout=timeout, user=http_login_user, passwd=http_login_password,
                        validate_certs=validate_certs)
        zbx.login(login_user, login_password)
    except Exception as e:
        module.fail_json(msg="Failed to connect to Zabbix server: %s" % e)
    host = Host(module, zbx)
    template_ids = []
    if link_templates:
        template_ids = host.get_template_ids(link_templates)
    group_ids = []
    if host_groups:
        group_ids = host.get_group_ids_by_group_names(host_groups)
    ip = ""
    if interfaces: