Update ruby19 :version in config/ruby_installer.rb

In the previous update to the ruby_installer.rb in config, only the files array was updated to 1.9.3-p484, the :version was not updated. This commit updates the :version to match the expected patchlevel of the tarball source.
Merge pull request #196 from haus/patch-1

Update ruby19 :version in config/ruby_installer.rb