<!--- 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 -->
The word "ERROR" in an IOS log message causes terminal to parse an error. IOS_command modules doesn't register stdout, only the one line of log output with the word "Error" as stderr. Task fails.
##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
I'm using ios_command module, however, I believe the ios terminal plugin has the regex to parse stderr.  ansible/lib/ansible/plugins/terminal/ios.py 
##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
Using 2.7.7. Difficult to copy and paste due to locked down environment.
```

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

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->
Ubuntu 16.04.6

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->
Use ios_command module to show logs in buffer on the device. Register the output as a variable. Debug the contents of the variable. If a line of logs contains the word "ERROR", the task will fail and stdout will be empty.

Actual log lines that have triggered this:
%IPSEC-3-REPLAY_ERROR: IPSec SA recieves anti-replay error, DP Handle 549, src_addr x.x.x.x, dest_addr y.y.y.y, SPI...

ISAKMP-ERROR: (0):Failed to find peer index node to update peer_info_list

<!--- Paste example playbooks or commands between quotes below -->
```yaml
- tasks
  ios_command:
    commands: show logging
  register: logs
```

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

##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
Lines of logs registered in variable.stdout.

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->
Variable has no stdout, only stderr. Stderr is only the one line of logs that contained the word "ERROR".
<!--- Paste verbatim command output between quotes -->
```paste below

```

super(Connection, self).__init__(play_context, new_stdin, *args, **kwargs)
        self._ssh_shell = None
        self._matched_prompt = None
        self._matched_cmd_prompt = None
        self._matched_pattern = None
        self._last_response = None
        self._history = list()
        self._command_response = None
        self._terminal = None
        self.cliconf = None
        self.paramiko_conn = None
        if self._play_context.verbosity > 3:
            logging.getLogger('paramiko').setLevel(logging.DEBUG)
        if self._network_os:
            self.cliconf = cliconf_loader.get(self._network_os, self)
            if self.cliconf:
                self.queue_message('vvvv', 'loaded cliconf plugin for network_os %s' % self._network_os)
                self._sub_plugin = {'type': 'cliconf', 'name': self._network_os, 'obj': self.cliconf}
            else:
                self.queue_message('vvvv', 'unable to load cliconf for network_os %s' % self._network_os)
        else:
            raise AnsibleConnectionFailure(
                'Unable to automatically determine host network os. Please '
                'manually configure ansible_network_os value for this host'
            )
        self.queue_message('log', 'network_os is set to %s' % self._network_os)
    def _get_log_channel(self):