Deleted 3 old and low rated notes

Following were the 3 notes with a rating less than -5 and
are older than 1 year.

These notes represented 0.0% of the 17869 total user notes,
and have now been removed.

Rating | Note
-------+---------------------------------------------------------
   -6  | https://php.net/manual/en/function.imagetypes.php#76791
   -6  | https://php.net/manual/en/function.strrpos.php#71401
   -6  | https://php.net/manual/en/function.strtok.php#91532