-fix #3510, ensure revocation test times out

git-svn-id: https://gnunet.org/svn/gnunet@34458 140774ce-b5e7-0310-ab8b-a85725594a96
-handle msg NULL

git-svn-id: https://gnunet.org/svn/gnunet@34459 140774ce-b5e7-0310-ab8b-a85725594a96