Use https in ado:OrganizationUrl

[jiasli]

The instruction clearly says ado:OrganizationUrl should use HTTPS.

azure-devops-auth-samples/ManagedClientConsoleAppSample/README.md

Line 59 in 49f055d

1. Find the key `ado:OrganizationUrl` and replace the existing value to the URL of your Azure DevOps organization; NOTE: This must use HTTPS.

Using http://dev.azure.com/organization causes confusion and leads to failure:

# PowerShell
> az rest --url '"http://dev.azure.com/azure-sdk/_apis/projects?stateFilter=All&api-version=2.2"' --resource 499b84ac-1321-427f-aa17-267ca6975798

... Microsoft Internet Explorer's Enhanced Security Configuration is currently enabled on your environment. This enhanced level of security prevents our web integration experiences from displaying or performing correctly. To continue with your operation please disable this configuration or contact your administrator. ...