Using strpos() right

One of our customers experienced issues with this plugin whenever the [category_id=]-marker is placed directly at the beginning of the content.

We have tracked this down to an invalid usage of strpos(): strpos() will return zero (“0”) if the marker is directly at the beginning of the content, which evaluates to false if compared as equal to a boolean. Comparing as identical will solve the problem.

Please see <https://php.net/manual/en/function.strpos.php&gt; for reference.