Log Message:
ruby-http: update to 3.3.0.

pkgsrc changes:
- update HOMEPAGE (follow renamed github)

Upstream changes (from CHANGES.md):

## 3.3.0 (2018-04-25)

This version backports some of the fixes and improvements made to development
version of the HTTP gem:

* [#458](https://github.com/httprb/http/pull/458)
  Extract HTTP::Client#build_request method.
  ([@tycoon])

## 3.2.1 (2018-04-24)

* [#468](https://github.com/httprb/http/pull/468)
  Rewind `HTTP::Request::Body#source` once `#each` is complete.
  ([@ixti])

## 3.2.0 (2018-04-22)

This version backports one change we missed to backport in previous release:

* Reduce memory usage when reading response body
  ([@janko-m])

## 3.1.0 (2018-04-22)

This version backports some of the fixes and improvements made to development
version of the HTTP gem:

* Fix for `#readpartial` to respect max length argument.
  ([@janko-m], [@marshall-lee])

* Fix for `HTTP::Request#headline` to allow two leading slashes in path.
  ([@scarfacedeb])

* Fix query string building for string with newlines.
  ([@mikegee])

* Deallocate temporary strings in `Response::Body#to_s`.
  ([@janko-m])

* Add `Request::Body#source`.
  ([@janko-m])