Clarified some instructions when ant can't be loaded.
Clarified some instructions when ant can't be loaded.

k-yamada/jruby-safe,jwo/jruby-sandbox,nilbus/jruby-sandbox,omghax/jruby-sandbox,Telmate/jruby-sandbox,Telmate/jruby-sandbox,k-yamada/jruby-safe,mwiley/jruby-sandbox,mwiley/jruby-sandbox,omghax/jruby-sandbox,nilbus/jruby-sandbox,jwo/jruby-sandbox