[BUG] cmd_monitor use tokio::signal::unix which do not exist under windows

**Describe the bug**
cmd_monitor use `tokio::signal::unix` which do not exist under windows

**To Reproduce**
Steps to reproduce the behavior:
1. make build
2. get the error
```rust
use tokio::signal::unix::{signal, SignalKind};
   |                    ^^^^ could not find `unix` in `signal`
```

**Expected behavior**
run `make build` under windows without error
