<!--- 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

```

command_prompt_matched = False
                    
                    signal.signal(signal.SIGALRM, self._handle_command_timeout)
                    signal.alarm(command_timeout)
                except AnsibleCmdRespRecv:
                    
                    self._ssh_shell.settimeout(cache_socket_timeout)
                    return self._command_response
            else:
                data = self._ssh_shell.recv(256)
                self._log_messages("response-%s: %s" % (window_count + 1, data))
            
            if not data:
                break
            recv.write(data)
            offset = recv.tell() - 256 if recv.tell() > 256 else 0
            recv.seek(offset)
            window = self._strip(recv.read())
            window_count += 1
            if prompts and not handled:
                handled = self._handle_prompt(window, prompts, answer, newline, False, check_all)
                matched_prompt_window = window_count
            elif prompts and handled and prompt_retry_check and matched_prompt_window + 1 == window_count:
                
                
                
                if self._handle_prompt(window, prompts, answer, newline, prompt_retry_check, check_all):
                    raise AnsibleConnectionFailure("For matched prompt '%s', answer is not valid" % self._matched_cmd_prompt)
            if self._find_prompt(window):
                self._last_response = recv.getvalue()