##### 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}
```

result = self._zapi.host.get({'filter': {'host': host_name}})
        return result
    
    def check_host_group_exist(self, group_names):
        for group_name in group_names:
            result = self._zapi.hostgroup.get({'filter': {'name': group_name}})
            if not result:
                self._module.fail_json(msg="Hostgroup not found: %s" % group_name)
        return True
    def get_template_ids(self, template_list):
        template_ids = []
        if template_list is None or len(template_list) == 0:
            return template_ids
        for template in template_list:
            template_list = self._zapi.template.get({'output': 'extend', 'filter': {'host': template}})
            if len(template_list) < 1:
                self._module.fail_json(msg="Template not found: %s" % template)
            else:
                template_id = template_list[0]['templateid']
                template_ids.append(template_id)
        return template_ids
    def add_host(self, host_name, group_ids, status, interfaces, proxy_id, visible_name, description, tls_connect,
                 tls_accept, tls_psk_identity, tls_psk, tls_issuer, tls_subject, ipmi_authtype, ipmi_privilege,
                 ipmi_username, ipmi_password):
        try:
            if self._module.check_mode:
                self._module.exit_json(changed=True)