Fix bug in force-unwrapping when resetting timers

When running tests locally, this error can surface.

```
---- test::agent_test::custom_resolver stdout ----
thread 'test::agent_test::custom_resolver' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 22, kind: InvalidInput, message: "Invalid argument" }', src/stream.rs:60:13
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```

The problem is that setting the timeouts might fail, and this is done
in a From trait where there is not possibility to "bubble" the
io::Error.

```
socket.set_read_timeout(None).unwrap();
socket.set_write_timeout(None).unwrap();
```

This commit moves the resetting of timers to an explicit `Stream::reset()` fn
that must be called every time we're unwrapping the inner stream.

src/unit.rs

@@ -238,9 +238,12 @@ pub(crate) fn connect(
 
     debug!("response {} to {} {}", resp.status(), method, url);
 
+    let mut stream: Stream = stream.into();
+    stream.reset()?;
+
     // since it is not a redirect, or we're not following redirects,
     // give away the incoming stream to the response object.
-    crate::response::set_stream(&mut resp, url.to_string(), Some(unit), stream.into());
+    crate::response::set_stream(&mut resp, unit.url.to_string(), Some(unit), stream);
 
     // release the response
     Ok(resp)