fixes #1715 logger compatibility with PHP 8.1

include/Logger.class.php

@@ -364,7 +364,7 @@ class Logger
   {
     $originalTime = microtime(true);
     $micro = sprintf('%06d', ($originalTime - floor($originalTime)) * 1000000);
-    $date = new DateTime(date('Y-m-d H:i:s.'.$micro, $originalTime));
+    $date = new DateTime(date('Y-m-d H:i:s.'.$micro, intval($originalTime)));
     return $date->format($this->options['dateFormat']);
   }