[RELEASE] Small bugfix release.

Changelog: 5.2.0...5.2.1

Author: fnagel

ext_emconf.php

@@ -18,7 +18,7 @@
     'author_email' => '[email protected]',
     'state' => 'stable',
     'clearCacheOnLoad' => true,
-    'version' => '5.2.1-dev',
+    'version' => '5.2.1',
     'constraints' => [
         'depends' => [
             'php' => '7.4.0-8.3.99',