emit warning along with unmatched line

### Is your feature request related to a problem? Please describe.

Hello, we use emit_unmatched so user knows which ip/host sent the failed syslog message. Can the warning message (failed to parse/ invalid syslog/ etc) be added to the emit_unmateched message as well?

### Describe the solution you'd like

Add the logged warning message to emit_unmatched

### Describe alternatives you've considered

None

### Additional context

_No response_