Update index.html.markdown

[danielmkn]

'/artifactory' needs to be added to the URL value, otherwise user will get 404.

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[bclodius]

@danielmkn In my case I also had to add https:// not sure if it defaults to http://

provider "artifactory" {
  url      = "https://artifactory.some.corporation.com/artifactory/"
  username = "redacted"
  password = "redacted"
}