Fix wrong type comparison rb_encoding for ruby encoding index

git-svn-id: https://svn.code.sf.net/p/rubycocoa/svn/trunk/src@2567 f4f36d40-9719-0410-9868-dde021a23eda
Fix wrong format type

git-svn-id: https://svn.code.sf.net/p/rubycocoa/svn/trunk/src@2568 f4f36d40-9719-0410-9868-dde021a23eda