Contact blocks configuration text is misleading

The configuration screen says:

Categories to be shown in the site wide contact form

However the selection a user makes are used to set the contact_form_blocks_site_wide_categories variable that is used for the generation of the blocks.
I could find no trace of any code removing categories from the site wide contact form.

I suggest updating the text to something like

Select the categories you would like to use as contact form blocks

and update the readme file and project description.

If this "Categories to be shown in the site wide contact form" functionality is desirable I would use a new variable and use reverse logic "Categories to be disabled in the site wide contact form" makes it clear that the contact form will act normally unless you specifically tell it otherwise.