Deleted 4 old and low rated notes

Following were the 4 notes with a rating less than -5 and
are older than 1 year.

These notes represented 0.0% of the 17336 total user notes,
and have now been removed.

Rating | Note
-------+---------------------------------------------------------
   -8  | https://php.net/manual/en/json.installation.php#124892
   -6  | https://php.net/manual/en/function.spl-autoload-register.php#112260
   -6  | https://php.net/manual/en/function.base64-decode.php#38479
   -6  | https://php.net/manual/en/function.log.php#45796