Fix integrated subscription editor record field

When trying to edit a subscription using the new 'integrated' editor,
it foolishly tries to populate an unfiltered bre dropdown selector.
This works OK in test environments, but (as expected) fails miserably
with production-size data sets.

The end result is that the dropdown either never populates, or takes
a really long time.  If the user saves before the dropdown loads, the
associated record ID is lost, and the subscription is no longer
properly associated with the record.

To fix this, simply turn the dropdown into a disabled text input
instead, as the ability to edit this field would generally be more
harmful than it is necessary.

Signed-off-by: Dan Wells <dbw2@calvin.edu>
Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>