passenger-install-apache2-module doesn't work on ruby 2.0

Now passenger-install-apache2-module failed on ruby 2.0

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Checking for required software...

 * GNU C++ compiler... found at /usr/bin/g++
 * Curl development headers with SSL support... found
 * OpenSSL development headers... found
 * Zlib development headers... found
 * Ruby development headers... found
 * OpenSSL support for Ruby... found
 * RubyGems... found
 * Rake... found at /opt/ruby/2.0/bin/rake
 * rack... found
 * Apache 2... found at /usr/sbin/apache2
 * Apache 2 development headers... found at /usr/bin/apxs2
 * Apache Portable Runtime (APR) development headers... found at /usr/bin/apr-1-config
 * Apache Portable Runtime Utility (APU) development headers... found at /usr/bin/apu-1-config

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Compiling and installing Apache 2 module...
(Omitted)

rake aborted!
cannot load such file -- rubygems/builder

(See full trace by running task with --trace)

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It looks like something went wrong


This patch will fix this issue.
So, passenger will well done on ruby 1.9 and 2.0.