Update to LibSass v3.6.3

Fixes #6862

resources/resource_transformers/tocss/scss/client_notavailable.go

@@ -0,0 +1,30 @@
+// Copyright 2020 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !extended
+
+package scss
+
+import (
+	"github.com/gohugoio/hugo/resources"
+	"github.com/gohugoio/hugo/resources/resource"
+)
+
+func (c *Client) ToCSS(res resources.ResourceTransformer, opts Options) (resource.Resource, error) {
+	return res.Transform(resources.NewFeatureNotAvailableTransformer(transformationName, opts))
+}
+
+// Used in tests.
+func Supports() bool {
+	return false
+}