clean up WebSocket.disconnect parameter
clean up WebSocket.disconnect parameter

Now the parameter is properly an Optional<NSTimeInterval>, nil means no timeout, and zero means close immediately and forcibly.

nuclearace/Starscream,daltoniam/Starscream,nuclearace/Starscream,nuclearace/Starscream,pvzig/Starscream,daltoniam/Starscream,daltoniam/Starscream,pvzig/Starscream