Remove type hint for class property counter

src/MDOutputHandler.php

@@ -18,7 +18,7 @@ final class MDOutputHandler {
     /** @var string */
     private string $_logfile;
     /** @var integer */
-    private int $_counter = 0;
+    private $_counter = 0;
     /** @var boolean */
     private bool $_file_logging = false;
     /** @var float */
@@ -103,7 +103,7 @@ final class MDOutputHandler {
     final public function toLog(string $msg, int $statusCode = 0):void {
 
         // Get parts for generating the message to log.
-        $this->_counter++;              // Increment counter
+        ++$this->_counter;              // Increment counter
         $date = \date("Y-m-d H:i:s");    // Get current date & time.
 
         switch ($statusCode) {