Make the default the same as where it actually gets used.

When used in includes/callbacks.inc, it was using a different
field... This lead to confusion as to why the query was not working,
because the admin page was indicating that it should have been one
value, but another was getting used because there had been none
explicitly set, and so the mismatched defaults made for a bad day.
Merge pull request #30 from adam-vessey/7.x-fix-default

Make the default the same as where it actually gets used.