Correct the time comparison for remember_me token

Corrects the time comparison to be `Time.now < time` which allows the user to
be set only when the current time is less than the 2 week window given in the
example.

activesupport/lib/active_support/message_verifier.rb

@@ -15,7 +15,7 @@ module ActiveSupport
   # In the authentication filter:
   #
   #   id, time = @verifier.verify(cookies[:remember_me])
-  #   if time < Time.now
+  #   if Time.now < time
   #     self.current_user = User.find(id)
   #   end
   #