fix: call after_handlers for legitimate requests without body part

[junekhan]

This PR fixes #764

[witcherofthorns]

Great! But, unfortunately, the "Access-Control-Allow-Origin" header does not appear in the response, although I see that it is placed in http_response.h, this is the last problem that remains related to CORS

Crow log:

[DEBUG] [http_response]: add_headerAccess-Control-Allow-Origin | http://localhost:8080
[DEBUG] [http_response]: add_headerAccess-Control-Allow-Methods | *
[DEBUG] [http_response]: add_headerAccess-Control-Allow-Headers | Accept, Origin, Content-Type, Authorization
[DEBUG] [http_response]: add_headerAccess-Control-Max-Age | 5
[DEBUG] [http_response]: add_headerAccess-Control-Allow-Credentials | true

Frontend server-response:

HTTP/1.1 204 No Content
Access-Control-Max-Age: 5
Access-Control-Allow-Headers: Accept, Origin, Content-Type, Authorization
Access-Control-Allow-Methods: *
Access-Control-Allow-Credentials: true

In any case, thank you very much! 👏 I somehow didn’t think to look at http_connection.h and see that there is need_to_call_after_handlers_