##### 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}
```

description:
                    - IP address used by host interface.
                    - Required if I(useip=1).
                default: ''
            dns:
                type: str
                description:
                    - DNS name of the host interface.
                    - Required if I(useip=0).
                default: ''
            port:
                type: str
                description:
                    - Port used by host interface.
                    - If not specified, default port for each type of interface is used
                    - 10050 if I(type='agent')
                    - 161 if I(type='snmp')
                    - 623 if I(type='ipmi')
                    - 12345 if I(type='jmx')
            bulk:
                type: int
                description:
                    - Whether to use bulk SNMP requests.
                    - 0 (don't use bulk requests), 1 (use bulk requests)
                choices: [0, 1]
                default: 1
        default: []
    tls_connect:
        description:
            - Specifies what encryption to use for outgoing connections.