adding TCP_STEALTH option to default configuration

git-svn-id: https://gnunet.org/svn/gnunet@34398 140774ce-b5e7-0310-ab8b-a85725594a96
-use const for the array

git-svn-id: https://gnunet.org/svn/gnunet@34399 140774ce-b5e7-0310-ab8b-a85725594a96