Skip respond_to check so rack.input doesn't have to implement it

actionpack/lib/action_controller/rack_ext.rb

@@ -6,8 +6,8 @@ def parse_multipart_with_rewind(env)
           result = parse_multipart_without_rewind(env)
 
           begin
-            env['rack.input'].rewind if env['rack.input'].respond_to?(:rewind)
-          rescue Errno::ESPIPE
+            env['rack.input'].rewind
+          rescue NoMethodError, Errno::ESPIPE
             # Handles exceptions raised by input streams that cannot be rewound
             # such as when using plain CGI under Apache
           end