Fix the column header mismatch in edgeryders.eu topic lists

[tanius]

On edgeryders.eu in any topic list of a category that had sub-categories (example) we had the issue also described here that a "Category" column header was present in the topic list, but not in the list entries.

As a workaround, the "Add Category Column" theme component has been installed, which adds the "Category" column back. (Which means, this is not an urgent issue to fix.)

However, since the issue is not present after enabling safe mode, it must be due to a theme or theme component that we installed and that "is overriding the whole template" as Sam says. Which should be fixed, then.

The fix should remove the "Category" column header, so that the topic list then omits the category column completely, as is the standard in recent Discourse versions.