Fix ruby_rake_task signature

Pre-compiling assets with Rails 3.2.9 doesn't work without this fix because the `ruby_rake_task` that's overridden in the rake tasks doesn't have the second argument to the function.  Without this fix, the pre-compilation yields this error:

```
bundle exec rake RAILS_ENV=staging RAILS_GROUPS=assets assets:precompile --trace
** Invoke assets:precompile (first_time)
** Invoke requirejs:precompile:external (first_time)
** Invoke requirejs:test_node (first_time)
** Execute requirejs:test_node
** Execute requirejs:precompile:external
** Invoke requirejs:precompile:all (first_time)
** Invoke requirejs:precompile:prepare_source (first_time)
** Invoke requirejs:setup (first_time)
** Invoke assets:environment (first_time)
** Invoke requirejs:precompile:disable_js_compressor (first_time)
** Execute requirejs:precompile:disable_js_compressor
** Execute assets:environment
** Invoke environment (first_time)
** Execute environment
** Execute requirejs:setup
** Invoke requirejs:clean (first_time)
** Invoke requirejs:setup 
** Execute requirejs:clean
** Execute requirejs:precompile:prepare_source
** Invoke requirejs:precompile:generate_rjs_driver (first_time)
** Invoke requirejs:setup 
** Execute requirejs:precompile:generate_rjs_driver
** Invoke requirejs:precompile:run_rjs (first_time)
** Invoke requirejs:setup 
** Invoke requirejs:test_node (first_time)
** Execute requirejs:test_node
** Execute requirejs:precompile:run_rjs
** Invoke requirejs:precompile:digestify_and_compress (first_time)
** Invoke requirejs:setup 
** Execute requirejs:precompile:digestify_and_compress
** Execute requirejs:precompile:all
** Execute assets:precompile
** Invoke assets:precompile:all (first_time)
** Execute assets:precompile:all
** Invoke assets:precompile:primary (first_time)
** Invoke assets:environment (first_time)
** Execute assets:environment
** Invoke environment (first_time)
** Execute environment
** Invoke tmp:cache:clear (first_time)
** Execute tmp:cache:clear
** Execute assets:precompile:primary
rake aborted!
wrong number of arguments (2 for 1)
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/requirejs-rails-0.9.2/lib/tasks/requirejs-rails_tasks.rake:14:in `ruby_rake_task'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/actionpack-3.2.9/lib/sprockets/assets.rake:66:in `block (3 levels) in <top (required)>'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/task.rb:236:in `call'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/task.rb:236:in `block in execute'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/task.rb:231:in `each'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/task.rb:231:in `execute'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/task.rb:175:in `block in invoke_with_call_chain'
/Users/gurdotan/.rvm/rubies/ruby-1.9.3-p484/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/task.rb:168:in `invoke_with_call_chain'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/task.rb:161:in `invoke'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/requirejs-rails-0.9.2/lib/tasks/requirejs-rails_tasks.rake:31:in `invoke_or_reboot_rake_task'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/actionpack-3.2.9/lib/sprockets/assets.rake:29:in `block (2 levels) in <top (required)>'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/task.rb:236:in `call'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/task.rb:236:in `block in execute'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/task.rb:231:in `each'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/task.rb:231:in `execute'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/task.rb:175:in `block in invoke_with_call_chain'
/Users/gurdotan/.rvm/rubies/ruby-1.9.3-p484/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/task.rb:168:in `invoke_with_call_chain'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/task.rb:161:in `invoke'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/application.rb:149:in `invoke_task'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/application.rb:106:in `block (2 levels) in top_level'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/application.rb:106:in `each'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/application.rb:106:in `block in top_level'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/application.rb:115:in `run_with_threads'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/application.rb:100:in `top_level'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/application.rb:78:in `block in run'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/application.rb:165:in `standard_exception_handling'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/lib/rake/application.rb:75:in `run'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/gems/rake-10.1.0/bin/rake:33:in `<top (required)>'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/bin/rake:23:in `load'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/bin/rake:23:in `<main>'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/bin/ruby_executable_hooks:15:in `eval'
/Users/gurdotan/.rvm/gems/ruby-1.9.3-p484@backyard/bin/ruby_executable_hooks:15:in `<main>'
Tasks: TOP => assets:precompile:all
```