##### 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}
```

if self.check_interface_properties(exist_interfaces, interfaces):
            return True
        
        exist_template_ids = self.get_host_templates_by_host_id(host_id)
        if set(list(template_ids)) != set(exist_template_ids):
            return True
        if int(host['proxy_hostid']) != int(proxy_id):
            return True
        
        if visible_name:
            if host['name'] != visible_name and host['name'] != host_name:
                return True
        
        if description:
            if host['description'] != description:
                return True
        if inventory_mode:
            if host['inventory']:
                if int(host['inventory']['inventory_mode']) != self.inventory_mode_numeric(inventory_mode):
                    return True
            elif inventory_mode != 'disabled':
                return True
        if inventory_zabbix:
            proposed_inventory = copy.deepcopy(host['inventory'])
            proposed_inventory.update(inventory_zabbix)
            if proposed_inventory != host['inventory']:
                return True
        if tls_accept is not None and 'tls_accept' in host:
            if int(host['tls_accept']) != tls_accept:
                return True