merge revision(s) 44515: [Backport #9375]

	* lib/rubygems:  Update to RubyGems master 21e409d / RubyGems 2.2.1.
	  See http://rubygems.rubyforge.org/rubygems-update/History_txt.html
	  for a list of bug fixes.

	* test/rubygems:  ditto.


git-svn-id: svn+ssh://svn.ruby-lang.org/ruby/branches/ruby_2_1@44778 b2dd03c8-39d4-4d8f-98ff-823fe69b080e