Handle EPOLLRDHUP.
Handle EPOLLRDHUP.

This enables the event loop to detect a half close of a peer without the
necessity to read or write.

gatzka/cjet,mloy/cjet,gatzka/cjet,mloy/cjet,mloy/cjet,gatzka/cjet,gatzka/cjet,gatzka/cjet,mloy/cjet,mloy/cjet