net.http: http.request() promise now resolves with response (breaking change)

Promise mode is not (widely?) used, changing this now while we can, as it
improves usability of the API.

The request is now available as response.request, if needed.

net/http.lua

@@ -293,7 +293,8 @@ local function new(options)
 						if code == 0 then
 							reject(http_errors.new(body, { request = a }));
 						else
-							resolve({ request = b, response = a });
+							a.request = b;
+							resolve(a);
 						end
 					end);
 				end);