No logging with `--threads:on` compiling
## Normal case

I compiled and run this code.

```nim
import htmlgen
import jester

routes:
  get "/":
    resp h1("Hello world")
```

```bash
$ nim c main.nim
$ ./main
```

And send request.

```bash
$ curl http://localhost:5000
<h1>Hello world</h1>
```

Logging.

```bash
$ ./main
INFO Jester is making jokes at http://0.0.0.0:5000
Starting 1 threads
DEBUG GET /
DEBUG   200 OK {"content-type": @["text/html;charset=utf-8"]}
```

## Problem case 1

No logging with `--threads:on` compiling

```bash
$ nim c --threads:on main.nim
$ ./main
```

Send request.

```bash
$ curl http://localhost:5000
<h1>Hello world</h1>
```

No logging.

```bash
$ ./main
INFO Jester is making jokes at http://0.0.0.0:5000
Starting 4 threads
Listening on port 5000
# NO debug log
```

## Problem case 2

Add logging code.

```nim
import htmlgen
import jester

import logging # Add

routes:
  get "/":
    info "GET /" # Add
    resp h1("Hello world")
```

```bash
$ nim c --threads:on main.nim
$ ./main
```

Send request.

```bash
$ curl http://localhost:5000
<h1>Hello world</h1>
```

No request logging.

```bash
$ ./main
INFO Jester is making jokes at http://0.0.0.0:5000
Starting 4 threads
Listening on port 5000
# NO debug log
# NO info log
```

