FIX: correct return of endorsable categories (PR #38)

category_accepting_endorsements setting has string values like “true” or “false”. Even though it was registered as :boolean because column in database is a string:

register_category_custom_field_type(CategoryExperts::CATEGORY_ACCEPTING_ENDORSEMENTS, :boolean)

Comparing <> “” was not enough to ensure that category_accepting_endorsements is checked

In spec I just added new category with “false” to ensure it is not added to endorsable categories.