Suppress "No such file or directory - list" message

How to reproduce:

  1. Remove ~/.fluentd-ui/
  2. Run `bin/rails console`
  3. You will see the following output:

         bin/rails: No such file or directory - list
         Loading development environment (Rails 4.1.4)
         irb(main):001:0>
Merge pull request #72 from kou/suppress-list-not-found-message

Suppress "No such file or directory - list" message