Drop sampleresult.getbytes.headers_size and sampleresult.getbytes.body_real_size

[Philippe Mouawad]

Hello,
I propose to drop those 2 properties as:

   - Setting them to false does not work, see:
      - https://bz.apache.org/bugzilla/show_bug.cgi?id=61587
   - it looks like they were introduced to allow reverting to 2.5
   behaviour, I think we can now drop it
   - I am not sure they are even used as we didn't get any bug report for
   now while the bug looks to me critical when they are set to false

We have already a lot of properties, so 2 dropped will be a good thing.
Regards
-- 
Cordialement.
Philippe