##### 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}
```

host_list = self._zapi.host.get({'output': 'extend', 'selectInventory': 'extend', 'filter': {'host': [host_name]}})
        if len(host_list) < 1:
            self._module.fail_json(msg="Host not found: %s" % host_name)
        else:
            return host_list[0]
    
    def get_proxyid_by_proxy_name(self, proxy_name):
        proxy_list = self._zapi.proxy.get({'output': 'extend', 'filter': {'host': [proxy_name]}})
        if len(proxy_list) < 1:
            self._module.fail_json(msg="Proxy not found: %s" % proxy_name)
        else:
            return int(proxy_list[0]['proxyid'])
    
    def get_group_ids_by_group_names(self, group_names):
        group_ids = []
        if self.check_host_group_exist(group_names):
            group_list = self._zapi.hostgroup.get({'output': 'extend', 'filter': {'name': group_names}})
            for group in group_list:
                group_id = group['groupid']
                group_ids.append({'groupid': group_id})
        return group_ids
    
    def get_host_templates_by_host_id(self, host_id):
        template_ids = []
        template_list = self._zapi.template.get({'output': 'extend', 'hostids': host_id})
        for template in template_list:
            template_ids.append(template['templateid'])
        return template_ids
    
    def get_host_groups_by_host_id(self, host_id):