[FEATURE][DOBO-786] make sure the key extension exists

Author: iriks-it

Image/Adapter/Gd2.php

@@ -45,7 +45,7 @@ public function __construct(
     public function open($filename)
     {
         $pathInfo = pathinfo($filename);
-        if (!key_exists('extension', $pathInfo)
+        if (key_exists('extension', $pathInfo)
             && in_array($pathInfo['extension'], $this->settings->getExtraFiletypes())
         ) {
             parent::open($filename);
@@ -65,7 +65,7 @@ public function save($destination = null, $newName = null)
     {
         $fileName = $this->_prepareDestination($destination, $newName);
         $pathInfo = pathinfo($fileName);
-        if (!key_exists('extension', $pathInfo)
+        if (key_exists('extension', $pathInfo)
             && in_array($pathInfo['extension'], $this->settings->getExtraFiletypes())
         ) {
             parent::save($destination, $newName);