Fix healthcheck matcher can not capture

Fix healthcheck matcher can not capture
- good:
`sudo ngrep -W byline "" src host xx.xx.xx.xx | grep -v "match:"`
```
interface: en0 (xx.xx.xx.0/255.255.255.0)
filter: (ip) and ( src host xx.xx.xx.xx )
```

- bad:
`sudo ngrep -W byline  src host xx.xx.xx.xx | grep -v "match:"`
```
interface: en0 (xx.xx.xx.0/255.255.255.0)
filter: (ip) and ( host xx.xx.xx.xx )
match: src
```