Merge pull request #25498 from seamuslee001/5.59

[REF] Use Civi::statics in CRM_Utils_File instead of php static

CRM/Utils/File.php

@@ -352,8 +352,7 @@ class CRM_Utils_File {
    * @return bool
    */
   public static function isExtensionSafe($ext) {
-    static $extensions = NULL;
-    if (!$extensions) {
+    if (!isset(Civi::$statics[__CLASS__]['file_extensions'])) {
       $extensions = CRM_Core_OptionGroup::values('safe_file_extension', TRUE);
 
       // make extensions to lowercase
@@ -370,9 +369,10 @@ class CRM_Utils_File {
         unset($extensions['html']);
         unset($extensions['htm']);
       }
+      Civi::$statics[__CLASS__]['file_extensions'] = $extensions;
     }
     // support lower and uppercase file extensions
-    return (bool) isset($extensions[strtolower($ext)]);
+    return (bool) isset(Civi::$statics[__CLASS__]['file_extensions'][strtolower($ext)]);
   }
 
   /**