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

Email.php

@@ -266,7 +266,7 @@ public function priority(int $priority)
      */
     public function getPriority(): int
     {
-        [$priority] = sscanf($this->getHeaders()->getHeaderBody('X-Priority'), '%[1-5]');
+        [$priority] = sscanf($this->getHeaders()->getHeaderBody('X-Priority') ?? '', '%[1-5]');
 
         return $priority ?? 3;
     }