How do I remove the "add excerpt" field on the question form?

Question

I want to remove the "Add Excerpt" field on the question form. See below for what it looks like:

How I can remove or hide this field?

Comments

I was able to remove the field by running this query in the database:

update qa_options set content = 0 where title = 'it_excerpt_field_enable';
commit;

But I would expect there to be a setting available from the Admin options where I could enable/disable this feature without having to query the database directly.