Improve the error messaging

[timrattle]

If you configure the console tool to use a proxy server it refuses to use the proxy server and always connected directly to the configured openEQUELLA server. When trying to launch the admin console from the tool, after clicking the launch button it would ask for credentials for the openEQUELLA server, disappear and the return to the launch tool with no error, no message or any indication of what had happened. After adding our internal CA certs to the java keystore for the admin console tool, it was finally able to connect successfully to the upgraded instance. A simple error message from the tool would have been nice to help troubleshoot this issue.