rbinstall.rb: fix bundled gems location
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49238 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
rbinstall.rb: fix bundled gems location
bundled gems. [Fix GH-812]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49238 b2dd03c8-39d4-4d8f-98ff-823fe69b080e