Fixes RVM Wrapper out of date.

Ruby 1.9.2/1.9.3 gems are binary compatible with 1.9.1 so gems are often stored in a 1.9.1 directory. Passenger erroneously looked in the 'wrappers/1.9.1/ruby" folder, causing the 'RVM wrapper error', when 1.9.1 wasn't even installed.

Fixes issues 828 and 771 for me.

The wrappers have never been out of date!