I see your error is related to ssh connection to emulator port 6622.
Please make sure port forwarding rules during the setup process is done properly.
(Refer to the guide User Guide | webOS Open Source Edition)
If the setup process is successful, When you go to Virtualbox settings -> Network tab -> Port Forwarding option
Port Forwarding rules should be set as below.
Once the settings were updated, please restart emulator and try to execute SSH command again.