- use only once KEEPALIVE message


git-svn-id: https://gnunet.org/svn/gnunet@30911 140774ce-b5e7-0310-ab8b-a85725594a96
- remove old message types


git-svn-id: https://gnunet.org/svn/gnunet@30912 140774ce-b5e7-0310-ab8b-a85725594a96