Fix ruby test failure.  Followup to r1434875.

You get svn_node_unknown for kind if it's not requested via dirent_fields call
to svn_ra_get_dir2() now.

* subversion/bindings/swig/ruby/test/test_ra.rb:
  (test_session): Change expected value to match changes in API behavior.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1435432 13f79535-47bb-0310-9956-ffa450edef68