Better handling of max file upload size according to PHP settings

- Allow unlimited size
- Better parsing of PHP size

Fixes #4896

app/Controller/TaskFileController.php

@@ -40,7 +40,7 @@ class TaskFileController extends BaseController
 
         $this->response->html($this->template->render('task_file/create', array(
             'task' => $task,
-            'max_size' => $this->helper->text->phpToBytes(get_upload_max_size()),
+            'max_size' => get_upload_max_size(),
         )));
     }