Fix VPN connection issues

[jeswr]

When we try to connect to triplestores via a VPN we get an ERR_CONNECTION_RESET error

[jeswr]

Seems likely that it is because the server hosting the demo doesn't have an SSL certificate (see https://stackoverflow.com/questions/24931566/getting-error-in-console-failed-to-load-resource-neterr-connection-reset and https://stackoverflow.com/questions/22083453/console-errors-failed-to-load-resource-neterr-insecure-response).