fix #3392 as suggested by reporter

git-svn-id: https://gnunet.org/svn/libmicrohttpd@33156 140774ce-b5e7-0310-ab8b-a85725594a96
fix rare epoll/resume issue, also simplifying logic

git-svn-id: https://gnunet.org/svn/libmicrohttpd@33157 140774ce-b5e7-0310-ab8b-a85725594a96
fix #3391

git-svn-id: https://gnunet.org/svn/libmicrohttpd@33158 140774ce-b5e7-0310-ab8b-a85725594a96