registry/response: Add protocols to DL resp

registry/response/terraform_provider.go

@@ -45,6 +45,7 @@ type TerraformProviderPlatform struct {
 // structure for a provider platform with all details required to perform a
 // download.
 type TerraformProviderPlatformLocation struct {
+	Protocols           []string `json:"protocols"`
 	OS                  string   `json:"os"`
 	Arch                string   `json:"arch"`
 	Filename            string   `json:"filename"`