Remove unneeded noop call to imagedestroy

See: https://www.php.net/manual/en/migration85.deprecated.php
The imagedestroy() function has been deprecated, as GdImage objects are freed automatically.

Author: vmcj

webapp/src/Utils/Utils.php

@@ -761,9 +761,6 @@ public static function getImageThumb(string $image, int $thumbMaxSize, string $t
             return false;
         }
 
-        imagedestroy($orig);
-        imagedestroy($thumb);
-
         return $thumbstr;
     }