Previously,
```rust
async fn foo(_a: u32) {}
```
would compile to
```rust
fn foo() {/* something */}
```
This patches changes this behaviour to
```rust
fn foo(_a: u32) {/* something */}
```
by simply forwarding the input arguments.
This allows any test fixture library (e.g. `rstest`, cfr.
https://github.com/la10736/rstest/issues/85) to integrate with
actix::test.
