chocolatey/chocolatey — pull request #332 by Gab-km (2013-09-11 08:42:18+00:00)
Title: Modify the condition to validate $creds

`[net.CredentialCache]::DefaultCredentials` may return a default `System.Net.NetworkCredential` instance.
So `$creds` need to be check if it is created with a default constructor.