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##### SUMMARY

I'm trying to use `hcloud_server_info` module and I see the exception.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
module `hcloud_server_info`

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```
ansible 2.9.0
  config file = /home/andor/work/Enkora/ansible/ansible.cfg
  configured module search path = ['/home/andor/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/lib/python3.7/dist-packages/ansible
  executable location = /usr/local/bin/ansible
  python version = 3.7.3 (default, Apr  3 2019, 05:39:12) [GCC 8.3.0]
```
##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->

<!--- Paste example playbooks or commands between quotes below -->
```yaml
---
- hosts: localhost
  tasks:
    - name: collect hosts from hcloud api
      hcloud_server_info:
```

<!--- HINT: You can paste gist.github.com links for larger files -->

##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->


##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes -->
```
The full traceback is:
Traceback (most recent call last):
  File "/home/andor/.ansible/tmp/ansible-tmp-1573035298.4213414-249660851701701/AnsiballZ_hcloud_server_info.py", line 102,
 in <module>
    _ansiballz_main()
  File "/home/andor/.ansible/tmp/ansible-tmp-1573035298.4213414-249660851701701/AnsiballZ_hcloud_server_info.py", line 94, 
in _ansiballz_main
    invoke_module(zipped_mod, temp_path, ANSIBALLZ_PARAMS)
  File "/home/andor/.ansible/tmp/ansible-tmp-1573035298.4213414-249660851701701/AnsiballZ_hcloud_server_info.py", line 40, in invoke_module
    runpy.run_module(mod_name='ansible.modules.cloud.hcloud.hcloud_server_info', init_globals=None, run_name='__main__', alter_sys=False)
  File "/usr/lib/python3.7/runpy.py", line 208, in run_module
    return _run_code(code, {}, init_globals, run_name, mod_spec)
  File "/usr/lib/python3.7/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/tmp/ansible_hcloud_server_info_payload_x1rpfqer/ansible_hcloud_server_info_payload.zip/ansible/modules/cloud/hcloud/hcloud_server_info.py", line 214, in <module>
  File "/tmp/ansible_hcloud_server_info_payload_x1rpfqer/ansible_hcloud_server_info_payload.zip/ansible/modules/cloud/hcloud/hcloud_server_info.py", line 199, in main
  File "/tmp/ansible_hcloud_server_info_payload_x1rpfqer/ansible_hcloud_server_info_payload.zip/ansible/module_utils/hcloud.py", line 62, in get_result
  File "/tmp/ansible_hcloud_server_info_payload_x1rpfqer/ansible_hcloud_server_info_payload.zip/ansible/modules/cloud/hcloud/hcloud_server_info.py", line 146, in _prepare_result
AttributeError: 'NoneType' object has no attribute 'name'
```

I guess that's because the field `image` is `null` for my server:
```
andor@titude:~$ curl -s -H "Authorization: Bearer $HCLOUD_TOKEN" 'https://api.hetzner.cloud/v1/servers?name=test-hostname' | jq '.servers[0] | .server_type.name, .image, .datacenter.location.city'
"cx20-ceph"
null
"Nuremberg"
```
And ansible module `hcloud_server_info` [relies](https://github.com/ansible/ansible/blob/86e4dcbaedba396691c731b89865b7d850e24dc6/lib/ansible/modules/cloud/hcloud/hcloud_server_info.py#L158) that field should be not-null:
```
                    "image": to_native(server.image.name),
```
And at the same time in the Hetzner API Documentation:
![Screenshot_20191106_135956](https://user-images.githubusercontent.com/147300/68296639-c4cf3200-009d-11ea-9ee6-d6303219c378.png)

module = AnsibleHcloudServerInfo.define_module()
    is_old_facts = module._name == 'hcloud_server_facts'
    if is_old_facts:
        module.deprecate("The 'hcloud_server_facts' module has been renamed to 'hcloud_server_info', "
                         "and the renamed one no longer returns ansible_facts", version='2.13')
    hcloud = AnsibleHcloudServerInfo(module)
    hcloud.get_servers()
    result = hcloud.get_result()
    if is_old_facts:
        ansible_info = {
            'hcloud_server_facts': result['hcloud_server_info']
        }
        module.exit_json(ansible_facts=ansible_info)
    else:
        ansible_info = {
            'hcloud_server_info': result['hcloud_server_info']
        }
        module.exit_json(**ansible_info)
if __name__ == "__main__":
    main()