Update options.php

missing ! on line 944 causes custom field usage ...

I've submitted a pull request for this in NHPOptions, but it doesn't look like the project is being maintained any longer - apparently Redux Framework is a fork which is under active development: https://github.com/ghost1227/Redux-Framework.
adding static methods to Config to return indexable and nonindexable post statuses
Rewriting the post status hook section, in order to handle publishing and unpublishing posts with its respective indexing/non-indexing actions
following convention for filters in Config class