Format parse incorrect when concatenate two variables  toggle without spaces in log format

Hi, I have a log format like this:

```
$remote_addr [$time_local] "$host$request_uri" $status
```

currently `gonx` will parse the format as regexp:

```
^(?P<remote_addr>[^ ]*) \[(?P<time_local>[^]]*)\] "(?P<host>[^$]*)\$request_uri" (?P<status>[^ ]*)
```

the **$request_uri** that after **$host** is not parsed as a regexp.