##### SUMMARY
Rendering  string 
```
config:
      service: !unsafe '{{ SYSLOG_IDENTIFIER }}'
```
with
```
- name: place config
  copy:
    content: |
      {{ config | to_toml }}
    dest: "{{ config_file }}"
```
leads to 
```
service = [ "{", "{", " ", "S", "Y", "S", "L", "O", "G", "_", "I", "D", "E", "N", "T", "I", "F", "I", "E", "R", " ", "}", "}",]
```
instead of 
```
service = "{{ SYSLOG_IDENTIFIER }}"
```
I understand that filter to_toml is not part of ansible and get from https://github.com/sivel/toiletwater but in code of it it uses ansible code in import section.
https://github.com/sivel/toiletwater/blob/master/plugins/filter/toml.py#L10


##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
to_toml

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
 % ansible --version
ansible 2.9.11
  config file = None
  configured module search path = ['/home/ashirokih/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/ashirokih/python/lib/python3.8/site-packages/ansible
  executable location = /home/ashirokih/python/bin/ansible
  python version = 3.8.2 (default, Jul 16 2020, 14:00:26) [GCC 9.3.0]

```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```paste below
empty
```

##### OS / ENVIRONMENT
not relevant


##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->

<!--- Paste example playbooks or commands between quotes below -->
Rendering  string 
```yaml
config:
      service: !unsafe '{{ SYSLOG_IDENTIFIER }}'
```
with
```yaml
- name: place config
  copy:
    content: |
      {{ config | to_toml }}
    dest: "{{ config_file }}"
```
<!--- HINT: You can paste gist.github.com links for larger files -->

##### EXPECTED RESULTS
```
service = "{{ SYSLOG_IDENTIFIER }}"
```


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

<!--- Paste verbatim command output between quotes -->
```paste below
service = [ "{", "{", " ", "S", "Y", "S", "L", "O", "G", "_", "I", "D", "E", "N", "T", "I", "F", "I", "E", "R", " ", "}", "}",]
```

Probably i should ask @sivel 
raise AnsibleParserError(
                        'Invalid "vars" entry for "%s" group, requires a dict, found "%s" instead.' %
                        (group, type(data))
                    )
                for var, value in data.items():
                    self.inventory.set_variable(group, var, value)
            elif key == 'children':
                if not isinstance(data, MutableSequence):
                    raise AnsibleParserError(
                        'Invalid "children" entry for "%s" group, requires a list, found "%s" instead.' %
                        (group, type(data))
                    )
                for subgroup in data:
                    self._parse_group(subgroup, {})
                    self.inventory.add_child(group, subgroup)
            elif key == 'hosts':
                if not isinstance(data, MutableMapping):
                    raise AnsibleParserError(
                        'Invalid "hosts" entry for "%s" group, requires a dict, found "%s" instead.' %
                        (group, type(data))
                    )
                for host_pattern, value in data.items():
                    hosts, port = self._expand_hostpattern(host_pattern)
                    self._populate_host_vars(hosts, value, group, port)
            else:
                self.display.warning(
                    'Skipping unexpected key "%s" in group "%s", only "vars", "children" and "hosts" are valid' %
                    (key, group)
                )
    def _load_file(self, file_name):