url.full coming from req instead of ecs

https://github.com/elastic/ecs-logging-nodejs/blob/26aaa6a8e75dd1cfe73023e81f676ef0a526b111/helpers/lib/http-formatters.js#L59

It looks like `url` attribute is being set with information from `req` instead of `ecs` like the rest of the attributes. This is causing `full` to reflect a different address than `domain` in our environment. Would this be more appropriate?

`ecs.url.full = (socket && socket.encrypted ? 'https://' : 'http://') + ecs.headers.host + ecs.url.path`