[chore] Remove outdated comment

Author: chadlwilson

src/main/ruby/jruby/rack.rb

@@ -70,7 +70,6 @@ def context!; context || raise('no context available') end
   end
 end
 
-# TODO remove require 'jruby/rack/version' from jruby-rack in 1.2
 require 'jruby/rack/version' unless defined? JRuby::Rack::VERSION
 require 'jruby/rack/helpers'
 require 'jruby/rack/booter'