If response has a header, written status code is ignored

Describe the bug If at least one header is written in response and then status code, e.g. 404, then provided status code is ignored and is always 200. Without header, status code is correct.

To Reproduce Steps to reproduce the behavior:

Start socketify app with following implementation:
```
from socketify import App
```

def handler(response, req): response.write_header( "Access-Control-Allow-Origin", "*" ) response.write_status(404) response.end("Not found")

app = App() app.any("/*", handler) app.listen(3000, lambda config: print("Listening on port http://localhost:%d now\n" % config.port)) app.run()


2. Send any request to localhost:3000
3. Check status code, it is 200 instead of expected 404.

**Expected behavior**
Status code 404.

**Desktop (please complete the following information):**
 - OS: Linux

**Additional context**
Without `response.write_header` call, status code is 404 as expected.

cirospaciari / socketify.py

If response has a header, written status code is ignored #144