Fixed deferred accept with EPOLLRDHUP enabled (ticket #1278). Previously, the read event of the accepted connection was marked ready, but not available. This made EPOLLRDHUP-related code (for example, in ngx_unix_recv()) expect more data from the socket, leading to unexpected behavior. For example, if SSL, PROXY protocol and deferred accept were enabled on a listen socket, the client connection was aborted due to unexpected return value of c->recv().