that were internally closed and replaced by other ones. This happened during
reconnect attempts.
--
When reconnecting with SSL_OP_NO_SSLv2 (nsock_core.c:472), the libary closes the
fd of the current IOD, and replaces it by a new one.
The man page for epoll_ctl states that a close() on a fd makes it removed from
any epoll set it was in. Therefore, if epoll_ctl(EPOLL_CTL_MOD, ...) returns
ENOENT, we retry with EPOLL_CTL_ADD.