Workaround for handling HTTPS

According to lostisland/faraday#318, `Faraday::Adapter::NetHttp` cannot currently use HTTPS with `Addressable::URI` with no specific port. (We can use HTTPS with `https://example.com:443/`)
I thought that we should take care of this as a consumer of Faraday with Addressable.

This patch is workaround for that.