<!--- Verify first that your issue is not already reported on GitHub -->
<!--- Also test if the latest release and devel branch are affected too -->
<!--- Complete *all* sections as described, this form is processed automatically -->

##### SUMMARY
<!--- Explain the problem briefly below -->
While using a simple reproducer with either force_valid_group_names=silently or force_valid_group_names=always an unexpected exception is thrown:
Sample playbook:

```
---
- hosts: localhost
  connection: local
  gather_facts: false
  tasks: 
    - name: add a host to a group
      add_host:
        name: localhost
        groups: Not-Working
```

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
inventory
##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```
ansible --version
ansible 2.9.0.dev0
  config file = /opt/gmuniz/ansible.cfg
  configured module search path = [u'/root/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /opt/ansible-devel/ansible/lib/ansible
  executable location = /opt/ansible-devel/ansible/bin/ansible
  python version = 2.7.5 (default, Apr  9 2019, 14:30:50) [GCC 4.8.5 20150623 (Red Hat 4.8.5-36)]

```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```
ansible-config dump --only-changed
TRANSFORM_INVALID_GROUP_CHARS(/opt/gmuniz/ansible.cfg) = always

```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->
CentOs-7

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

<!--- Paste example playbooks or commands between quotes below -->
```
- hosts: localhost
  connection: local
  gather_facts: false
  tasks: 
    - name: add a host to a group
      add_host:
        name: localhost
        groups: Not-Working

```

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

##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
I expect the host to be added to the group either with the originally provided name or the replaced underscore name.

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

<!--- Paste verbatim command output between quotes -->
```
TASK [add a host to a group] *************************************************************************************************************************************************************************************
task path: /opt/gmuniz/add_host.yml:6
creating host via 'add_host': hostname=localhost
 [WARNING]: A duplicate localhost-like entry was found (localhost). First found localhost was localhost

 [WARNING]: Invalid characters were found in group names and automatically replaced, use -vvvv to see details

ERROR! Unexpected Exception, this is probably a bug: u'Not-Working'

```

play_context = play_context.set_task_and_variable_override(task=task, variables=all_vars, templar=templar)
            
            
            play_context.post_validate(templar=templar)
            
            
            if not play_context.remote_addr:
                play_context.remote_addr = target_host.address
            
            
            play_context.update_vars(all_vars)
            if task.when:
                self._cond_not_supported_warn(meta_action)
            if target_host in self._active_connections:
                connection = Connection(self._active_connections[target_host])
                del self._active_connections[target_host]
            else:
                connection = connection_loader.get(play_context.connection, play_context, os.devnull)
                play_context.set_attributes_from_plugin(connection)
            if connection:
                try:
                    connection.reset()
                    msg = 'reset connection'
                except ConnectionError as e:
                    
                    display.debug("got an error while closing persistent connection: %s" % e)
            else:
                msg = 'no connection, nothing to reset'
        else:
            raise AnsibleError("invalid meta action requested: %s" % meta_action, obj=task._ds)