Redcarpet not available with jruby (#19313).

git-svn-id: http://svn.redmine.org/redmine/branches/2.6-stable@14105 e93f8b46-1217-0410-a6f0-8f06a7374b81

test/unit/helpers/application_helper_test.rb

@@ -165,6 +165,7 @@ RAW
     end
   end
 
+  if Object.const_defined?(:Redcarpet)
   def test_attached_images_with_markdown_and_non_ascii_filename
     attachment = Attachment.generate!(:filename => 'café.jpg')
     with_settings :text_formatting => 'markdown' do
@@ -172,6 +173,7 @@ RAW
         textilizable("![](café.jpg)", :attachments => [attachment])
     end
   end
+  end
 
   def test_attached_images_filename_extension
     set_tmp_attachments_directory