fixing comment


git-svn-id: https://gnunet.org/svn/gnunet@33845 140774ce-b5e7-0310-ab8b-a85725594a96
forgotten commit making penalty quadratic as used and documented


git-svn-id: https://gnunet.org/svn/gnunet@33846 140774ce-b5e7-0310-ab8b-a85725594a96