[rubygems/rubygems] Check for :install_dir precedence over :user_install
:install_dir
:user_install
https://github.com/rubygems/rubygems/commit/6539da07aa
[rubygems/rubygems] Check for
:install_dirprecedence over:user_installhttps://github.com/rubygems/rubygems/commit/6539da07aa