Avoid showing "@ rb_sysopen" noise for Ruby 2.4.

This fixes cucumber#1071.

features/docs/getting_started.feature

@@ -9,7 +9,7 @@ Feature: Getting started
     When I run `cucumber`
     Then it should fail with:
       """
-      No such file or directory - features. You can use `cucumber --init` to get started.
+      Feature folder not found at
       """
 
   Scenario: Accidentally run Cucumber in a folder with Ruby files in it.

lib/cucumber/runtime.rb

@@ -30,8 +30,14 @@ def initialize(original_exception, path)
   class FileNotFoundException < FileException
   end
 
-  class FeatureFolderNotFoundException < FileException
-    include FixRuby21Bug9285 if Cucumber::RUBY_2_1 || Cucumber::RUBY_2_2 || Cucumber::RUBY_2_3
+  class FeatureFolderNotFoundException < Exception
+    def initialize(path)
+      @path = path
+    end
+
+    def message
+      "Feature folder not found at #{@path}"
+    end
   end
 
   require 'cucumber/core'
@@ -141,8 +147,8 @@ def initialize(path)
           set_encoding
         rescue Errno::EACCES => e
           raise FileNotFoundException.new(e, File.expand_path(path))
-        rescue Errno::ENOENT => e
-          raise FeatureFolderNotFoundException.new(e, path)
+        rescue Errno::ENOENT
+          raise FeatureFolderNotFoundException.new(File.expand_path(path))
         end
       end