Use port in request if specified.

When using knox with an S3 emulator such as fakes3[1], the port is
typically different from the default http/https ports (80/433).

This patch passes options.port to the http(s) options. Without this
patch, the request will be issued to the default port (80/433) and
result in an ECONNREFUSED error.

[1] https://github.com/jubos/fake-s3