<!--- 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

```

name = "p=%s u=%s | " % (os.getpid(), getpass.getuser())
        name += "paramiko [%s]" % self._play_context.remote_addr
        return name
    def get_prompt(self):
        """Returns the current prompt from the device"""
        return self._matched_prompt
    def exec_command(self, cmd, in_data=None, sudoable=True):
        
        
        
        
        if self._ssh_shell:
            try:
                cmd = json.loads(to_text(cmd, errors='surrogate_or_strict'))
                kwargs = {'command': to_bytes(cmd['command'], errors='surrogate_or_strict')}
                for key in ('prompt', 'answer', 'sendonly', 'newline', 'prompt_retry_check'):
                    if cmd.get(key) is True or cmd.get(key) is False:
                        kwargs[key] = cmd[key]
                    elif cmd.get(key) is not None:
                        kwargs[key] = to_bytes(cmd[key], errors='surrogate_or_strict')
                return self.send(**kwargs)
            except ValueError:
                cmd = to_bytes(cmd, errors='surrogate_or_strict')
                return self.send(command=cmd)
        else:
            return super(Connection, self).exec_command(cmd, in_data, sudoable)
    def update_play_context(self, pc_data):