Replace ob_end_clean to ob_clean in ErrorHandler class error_handler method.

exception/ErrorHandler.php

@@ -21,7 +21,7 @@ class ErrorHandler
     {
         $ob_handlers = ob_get_status();
         if (!empty($ob_handlers)) {
-            ob_end_clean();
+            ob_clean();
         }
         throw new ErrorException($errstr, 0, $errno, $errfile, $errline);
     }