Update lib/rack/lint.rb

Author: ioquatix

lib/rack/lint.rb

@@ -816,7 +816,7 @@ def check_rack_protocol_header(status, headers)
       ##
       ## === The Body
       ##
-      ## The Body is typically an +Array+ of +String+ values, an enumerable that yields +String+ values, a +Proc+, or a +File+-like object.
+      ## The Body is typically an +Array+ of +String+ values, an enumerable that yields +String+ values, a +Proc+, or an +IO+-like object.
       ##
       ## The Body must respond to +each+ or +call+. It may optionally respond to +to_path+ or +to_ary+. A Body that responds to +each+ is considered to be an Enumerable Body. A Body that responds to +call+ is considered to be a Streaming Body.
       ##