Upstream: fixed non-buffered proxying with eventport. For new data to be reported with eventport on Solaris, ngx_handle_read_event() needs to be called after reading response headers. To do so, ngx_http_upstream_process_non_buffered_upstream() now called unconditionally if there are no prepread data. This won't cause any read() syscalls as long as upstream connection is not ready for reading (c->read->ready is not set), but will result in proper handling of all events.