When socket.io is not able to close a connection somehow, the code
never reaches the final shutdown state but keeps waiting for all
connections to be closed. This can cause a high CPU load on failing
shutdown. It is very unlikely to happen, except when the server is
shut down exactly at the same time a socket is disconnecting and not
already marked as disconnected. This change adds a fallback timer
which forcefully kills the server after a certain amount of time.
Signed-off-by: Erik Michelson <github@erik.michelson.eu>
801ef14b7e