Merge branch '4.4' into 5.2

* 4.4:
  [Finder] Fix gitignore regex build with "**"
  Fixed deprecation warnings about passing null as parameter
  [Security] Keep Bulgarian wording consistent across all texts.
  Migrate configuration file for PHP CS Fixer 2.19/3.0
  [Form] Replace broken ServerParams mock

Author: fabpot

XPath/Extension/NodeExtension.php

@@ -157,7 +157,7 @@ public function translateElement(Node\ElementNode $node): XPathExpr
     {
         $element = $node->getElement();
 
-        if ($this->hasFlag(self::ELEMENT_NAME_IN_LOWER_CASE)) {
+        if ($element && $this->hasFlag(self::ELEMENT_NAME_IN_LOWER_CASE)) {
             $element = strtolower($element);
         }