MDL-70301 lib: Upgrade scssphp to 1.4.1

lib/scssphp/Formatter/Debug.php

@@ -1,8 +1,9 @@
 <?php
+
 /**
  * SCSSPHP
  *
- * @copyright 2012-2019 Leaf Corcoran
+ * @copyright 2012-2020 Leaf Corcoran
  *
  * @license http://opensource.org/licenses/MIT MIT
  *
@@ -12,12 +13,13 @@
 namespace ScssPhp\ScssPhp\Formatter;
 
 use ScssPhp\ScssPhp\Formatter;
-use ScssPhp\ScssPhp\Formatter\OutputBlock;
 
 /**
  * Debug formatter
  *
  * @author Anthon Pang <[email protected]>
+ *
+ * @deprecated since 1.4.0.
  */
 class Debug extends Formatter
 {
@@ -26,6 +28,8 @@ class Debug extends Formatter
      */
     public function __construct()
     {
+        @trigger_error('The Debug formatter is deprecated since 1.4.0.', E_USER_DEPRECATED);
+
         $this->indentLevel = 0;
         $this->indentChar = '';
         $this->break = "\n";