running the server with the certificate configuration better be activated with port parameter

on the last server running command on this codelab (section 7: Debug Overrides), it's better to include the port setting option, in case the user used port other than the default.
in the code lab:
`http-server ./data --ssl --cert root-ca.cert.pem --key root-ca.privkey.pem`
better be changed to:
`http-server ./data -p 8080 --ssl --cert root-ca.cert.pem --key root-ca.privkey.pem`